Om 904

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OM 904 LA – OM 906 LA – OM 924 LA – OM 926 LA Operating Instructions

Order no. 6462 9806 02 Part no. 906 584 11 81 EN Edition A 08/03

Thank you for choosing this Mercedes-Benz engine.

Please get to know your new Mercedes-Benz engine first. Make sure you read the Operating Instructions in particular before using the engine for the first t ime. In this way you can ensure successful and safe use. At the same time you will avoid endan-gering yourself and others when operating the engine.

Items of special equipment are marked with an asterisk *. The equipment in your Mercedes-Benz engine may vary, depend-ing on the version. Mercedes-Benz is con-stantly updating its engines to the state of

the art. You cannot, therefore, base any claims on the data, illustrations or descrip-tions in these Operating Instructions.

For further information contact a Mercedes-Benz Service Centre.

The Operating Instructions and Mainte-nance Booklet belong with the engine. You should therefore always keep them with the engine and pass them on to the new owner if you sell it.

The technical documentation team at DaimlerChrysler AG wishes you every suc-cess.

Contents

1 Introduction

The aim of these Operating Instructions . . . . . . . . . . . . . . . . . . . . . 5Symbols . . . . . . . . . . . . . . . . . . . . . . . . 6Protection of the environment . . . . . . 7Operating safety . . . . . . . . . . . . . . . . . 8

Correct use. . . . . . . . . . . . . . . . . . . . 9

2 At a glance

OM 904 LA/OM 924 LA . . . . . . . . . . 12OM 906 LA/OM 926 LA . . . . . . . . . . 16Location of sensors . . . . . . . . . . . . . . 20Engine plate . . . . . . . . . . . . . . . . . . . . 22

3 Before commissioning

General . . . . . . . . . . . . . . . . . . . . . . . . 24Type designation . . . . . . . . . . . . . . 24Engine data card. . . . . . . . . . . . . . . 24Description of the engine . . . . . . . . 25Flame-start system*. . . . . . . . . . . . 26Grid heater* . . . . . . . . . . . . . . . . . . 27Exhaust brake/constantly-open throttle valve*. . . . . . . . . . . . . . . . . 28Telligent® engine system . . . . . . . . 29

Transport and installation . . . . . . . . 33

4 Safety

Safety precautions. . . . . . . . . . . . . . . 36Personnel qualifications . . . . . . . . . . 37Conversion parts and modifications . . . . . . . . . . . . . . . . . . . 38Safety/emergency running programs . . . . . . . . . . . . . . . . . . . . . . 39Genuine Mercedes-Benz parts . . . . . 40

5 Operation

Commissioning. . . . . . . . . . . . . . . . . . 42Preparation. . . . . . . . . . . . . . . . . . . 42Starting the engine for the first time . . . . . . . . . . . . . . . . . . . . . . . . 44Starting the engine . . . . . . . . . . . . . 47

Monitoring engine operation . . . . . . 49Charge current . . . . . . . . . . . . . . . . 49Telligent® engine system . . . . . . . . 50Flame-start system*. . . . . . . . . . . . 50Grid heater* . . . . . . . . . . . . . . . . . . 51

Stopping the engine. . . . . . . . . . . . . . 52Winter operation . . . . . . . . . . . . . . . . 53

Cleaning/protective treatment . . . . 55Cleaning the engine . . . . . . . . . . . . 55Cleaning the cooling system . . . . . . 56Protective treatment. . . . . . . . . . . . 58

Service products . . . . . . . . . . . . . . . . 59Diesel fuels . . . . . . . . . . . . . . . . . . . 60Engine oils . . . . . . . . . . . . . . . . . . . 62Coolant . . . . . . . . . . . . . . . . . . . . . . 63

6 Maintenance

Maintenance instructions . . . . . . . . . 66Overview of work plans . . . . . . . . . . . 67

Maintenance service . . . . . . . . . . . . 67Additional work . . . . . . . . . . . . . . . . 67Additional work during every 3rd maintenance service . . . . . . . . 67

Work plans . . . . . . . . . . . . . . . . . . . . . 68Engine: Checking for leaks and general condition . . . . . . . . . . . . . . 68Lines and hoses on the engine: Checking for leaks and general condition . . . . . . . . . . . . . . . . . . . . . 68Engine: Oil change and filter replacement . . . . . . . . . . . . . . . . . . 69Adjusting the valve clearance . . . . . 73

Contents

Fuel prefilter: Cleaning the filter element. . . . . . . . . . . . . . . . . . . . . . 77Fuel prefilter with heated water separator*: Replacing the filter element. . . . . . . . . . . . . . . . . . . . . . 78Replacing the fuel filter element. . . 80Intake pipe between air cleaner and engine: Checking for leaks and general condition . . . . . . . . . . . 82Poly-V-belt: Checking the condition. . . . . . . . . . . . . . . . . . 83Engine brake: Checking the condition and setting . . . . . . . . . . . 88Engine cooling system: Checking and correcting the fluid level and the antifreeze/corrosion inhibitor . . . . . . . . . . . . . . . . . . . . . 90Cooling and heating system: Checking for leaks and general condition. . . . . . . . . . . . . . . . . . . . . 91Renewing coolant. . . . . . . . . . . . . . 94

7 Practical advice

Malfunctions, causes and solutions . . . . . . . . . . . . . . . . . . . . . . . 98Jump-starting . . . . . . . . . . . . . . . . . . 106

8 Technical data

Engine data . . . . . . . . . . . . . . . . . . . . 108Test values and adjustment values . . . . . . . . . . . . . . . . . . . . . . . . 112Tightening torques . . . . . . . . . . . . . . 113

9 Glossary and index

Technical terms . . . . . . . . . . . . . . . . 115Index . . . . . . . . . . . . . . . . . . . . . . . . . 117

The aim

Introduction

of these Operating Instructions

� The aim of these Operating Instructions

1
These Operating Instructions are intended to assist you in all situations with your new engine. Each section has a list of contents to help you find the information you re-quire quickly:
2 At a glance

This section gives you an overview of the layout of important components in the en-gine.

3 Before commissioning

This contains the basic information you re-quire for initial operation. If this is your first Mercedes-Benz engine, you should read this section first.

4 Safety

This section contains important aspects with regard to safety when handling Mercedes-Benz 900 series engines.

5 Operation

Here you will find all the information you will need when you are operating the en-gine.

6 Maintenance

This is where you will find more detailed in-formation about maintenance work.

7 Practical advice

Here you will find practical help for possi-ble problems.

8 Technical data

All the important technical data for the en-gine is listed here.

9 Glossary and index

The glossary of technical terms explains the most important technical concepts.

The index is intended to help you find infor-mation quickly.

The engine documentation comprises the following:

� these Operating Instructions

� the Maintenance Booklet

� Specifications for Service Products

You may receive additional supplements depending on the equipment.

5

Introduction

Symbols

1

� Symbols
You will find the following symbols used in these Operating Instructions:
* This asterisk indicates special equipment. Since not all models have the same standard equip-ment, the layout of your engine may differ from certain descriptions and i llustrations.

� This symbol means that you have to do something.

� A number of these symbols one after the other indicates a sequence of ac-tions.

� page This symbol indicates the page on which you will find further in-formation on the subject.

This continuation symbol indi-cates an interrupted sequence of actions that will be continued on the next page.

-> This symbol in the glossary of technical terms means that the term following the arrow is also explained.

Warning GA warning draws your attention to possible risks of accident and injury to yourself and others.

You should therefore always read and ob-serve all warning notices.

Environmental note HAn environmental note gives you tips on the protection of the environment.

!This note draws your attention to possi-ble hazards to your engine.

iThis tip contains advice or further infor-mation you may find useful.

��

6

Introduction

Protection of the environment

� Protection of the environment

1
Environmental note HDaimlerChrysler's declared policy is one of integrated environmental protection. This policy starts at the root causes and encom-passes in its management decisions all the consequences for the environment which could arise from production processes or the products themselves.
The objectives are for the natural resources which form the basis of our existence on this planet to be used sparingly and in a manner which takes the requirements of both nature and humanity into account.

Operate the engine in an environmentally-responsible manner, and you will help to protect the environment.

Fuel consumption and engine wear depend on the operating conditions.

Therefore you should:

� not warm up the engine at idle

� switch off the engine during waiting pe-riods imposed by operations

� monitor fuel consumption

� carry out the specified maintenance work regularly

7

Introduction

Operating safety

1

� Operating safety
The operating safety of an engine firstly de-pends on its proper installation into the complete system (e.g. vehicle, machine, etc.). Secondly, as operator or service per-sonnel, you also have a direct influence on the safe operation of the engine.
Some of the requirements for operating the engine safely can be achieved by ad-hering to the specified maintenance inter-vals and ensuring that the required maintenance work is carried out correctly.

However, safe engine operation also de-pends on correct servicing, such as check-ing the engine oil level at regular intervals.

Risk of accident GImproper operation of the engine, e.g. ex-ceeding the permitted maximum engine speed in overrun mode or operating the en-gine with too little oil, can cause engine damage. Engine damage can lead to an in-crease in the risk of accident.

Therefore, observe the notes on operating the engine in these Operating Instructions.

Risk of accident GFaulty maintenance work or failure to carry out maintenance work, e.g. not changing the oil filter or not observing the correct mainte-nance interval, can cause engine damage. Engine damage can lead to an increase in the risk of accident.

Therefore, observe the notes on engine maintenance in these Operating Instruc-tions.

8

Introduction

Operating safety

1
The engine is only designed for installation in accordance with the specifications de-termined in the contract.
The manufacturer of the end product is personally responsible for the complete system of the end product, and in particu-lar for the correct installation and compat-ibility of this engine with the complete system.

The engine must not be modified. DaimlerChrysler accepts no responsibil ity for damage caused as the result of modifi-cations.

Correct use of the engine includes adher-ing to these Operating Instructions, adher-ing to the maintenance intervals and performing maintenance work correctly in accordance with these Operating Instruc-tions.

Risk of accident GWork incorrectly carried out on electronic components and its software could impair the functioning of these components. Since the electronic systems are networked, this might also affect systems that have not been modified.

Always have work on or modifications to electronic components carried out at a qual-ified specialist workshop which has the nec-essary specialist knowledge and tools to carry out the work required.

Mercedes-Benz recommends that you use a Mercedes-Benz Service Centre for this pur-pose.

Correct use

9

10

At a glance

2

OM 904 LA /OM 924 LA

OM 906 LA /OM 926 LA

Location of sensors

Engine plate

11

At a glance

OM 904 LA/OM 924 LA

2

� OM 904 LA /OM 924 LA

12

At a glance

OM 904 LA/OM 924 LA

2

1 Fan2 Poly-V-belt tensioning pulley3 Coolant pump4 Charge pressure pipe (with flame-start

system*) from intercooler5 Charge pressure pipe to intercooler6 Crankcase ventilat ion system7 Heating delivery line* coolant l ine8 Oil fil ler neck9 Fuel filtera Fuel prefi lterb Dipstickc Air compressor (with power-steering

pump*)d Engine control unit

13

At a glance

OM 904 LA/OM 924 LA

2

14

At a glance

OM 904 LA/OM 924 LA

2

1 Flywheel housing2 Charge-air housing3 Oil fil ler neck4 Charge pressure pipe to intercooler5 Charge pressure pipe (with flame-start

system*) from intercooler6 Exhaust manifold7 Oil filter8 Exhaust gas turbocharger9 Alternatora Starter motor

15

At a glance

OM 906 LA/OM 926 LA

2

� OM 906 LA /OM 926 LA

16

At a glance

OM 906 LA/OM 926 LA

2

1 Fan2 Poly-V-belt tensioning pulley3 Coolant pump4 Heating forward line* coolant line5 Charge pressure pipe from intercooler6 Oil filter7 Charge pressure pipe to intercooler8 Oil fil ler neck9 Charge-air housinga Cylinder head coverb Fuel filterc Fuel prefi lterd Engine control unite Air compressor*f Dipstickg Power-steering pump

17

At a glance

OM 906 LA/OM 926 LA

2

18

At a glance

OM 906 LA/OM 926 LA

2

1 Starter motor2 Flywheel housing3 Exhaust gas turbocharger4 Exhaust manifold5 Charge-air housing6 Cylinder head cover7 Oil fil ler neck8 Charge pressure pipe to intercooler9 Charge pressure pipe from intercoolera Crankcase ventilat ion systemb Alternator

19

At a glance

Location of sensors

2

� Location of sensors
OM 904 LA/OM 924 LA (comparable to OM 906 LA/ OM 926 LA)
20

At a glance

Location of sensors

2

1 Oil pressure sensor2 Coolant temperature sensor3 Fuel temperature sensor4 TDC sensor (on the camshaft sprocket)5 Crankshaft position sensor (on the fly-

wheel)6 Combined charge-air /charge-air pres-

sure sensor

21

At a glance

Engine plate

2

� Engine plate
Location
The engine plate is located on the right-hand side of the engine at the rear under-neath the exhaust manifold (arrow).

Location of engine plate

22

Before commissioning

3

General

Transport and installation

23


General

3

� General

The engine data card (DIN A4 sheet) forms an integral part of the documents belong-ing to the engine and should always be kept with the Maintenance Booklet. It con-tains details about the engine's construc-tion, including special equipment features.

The engine data card must be produced for the procurement of genuine parts.

Engine data card

Type designation

OM 9XX L A

OM Oil engine (diesel en-gine)

9XX Engine type

L Intercooler

A Exhaust gas turbo-charger

Engine data card

iThe engine data card describes the scope of delivery from the factory from which the engine was shipped; later changes to the scope of delivery are not included on the data card.

Always keep the engine data card with the Maintenance Booklet.

24


General

3

The OM 904 LA/ OM 924 LA (4-cylinder) and OM 906 LA /OM 926 LA (6-cylinder) engines are water-cooled four-stroke die-sel injection engines.

The cylinders are arranged in-line and have separate fuel-injection pumps (unit pumps) with a short high-pressure fuel-injection l ine to the multi-hole nozzle locat-ed centrally in relation to the combustion chamber. The unit pumps are mounted di-rectly on the crankcase. They are driven by the camshaft roller tappets. Each cylinder has two inlet valves and one exhaust valve.

The engines are equipped with an exhaust gas turbocharger (sometimes with charge-pressure limiting) and intercooler as stand-ard. The engine can be optionally equipped with an engine brake* (throttle and con-stantly-open throttle valves).

Thanks to its fully electronic control sys-tem for controlling the injection quantity and injection timing via solenoid valves, this is a part icularly low-emission engine.

The control system comprises an engine-resident control module, an engine control (MR) and an application-related vehicle control unit (FR) or an adaptation module (ADM), all interconnected via the Control-ler Area Network (CAN).

Description of the engine

25


General

3

The flame-start system is a cold-start aid for starting at low outside temperatures. It reduces the white smoke emission after the engine is started. In addition, it reduc-es the strain on the starter motor and bat-teries by shortening the startup time.

Fuel can be ignited by a flame glow plug in-tegrated in the charge-air pipe from the in-tercooler. The fuel is supplied to the flame glow plug via a solenoid valve with a dosing jet.

Flame-start system

The flame-start system is primed after a preglow time (maximum 20 seconds) which is dependent on the outside temper-ature. After this time the flame-start sys-tem indicator lamp goes out.

Once the engine has started, the flame-start system is supplied with fuel by the en-gine's fuel delivery pump.

Flame-start system indicator lamp

The flame-start system is only operational if the engine is started within 30 seconds of the flame-start system indicator lamp going out.

Flame-start system*

26


General

3
See also the "Diesel fuels" section (� see page 60) and "Coolant" section (� see page 63) for operation of the en-gine at low outside temperatures.
The grid heater is a cold-start aid for start-ing at low outside temperatures. The charge-air is preheated by a heater strip in-tegrated in the charge-air pipe from the in-tercooler. In addition, it reduces the strain on the starter motor and battery by short-ening the startup t ime.

The white smoke limit is reduced by a run-on heating time of up to 180 seconds after starting the engine.

!If the flame-start system indicator lamp does not go out after more than 20 sec-onds there is a malfunction in the flame-start system.

Grid heater*

27


General

3

To increase braking power, the engine can be equipped with an engine brake valve on the exhaust gas turbocharger in conjunc-tion with constantly-open throttle valves on the cylinders.

While the exhaust gas back pressure from the engine brake valve is used to increase the braking power, the constantly-open throttle valves cause a pressure reduction in the working cycle (3rd cycle), while com-pression (2nd cycle) is practically unaffect-ed.

The constantly-open throttle valves are small valves in the cylinder head and locat-ed on the side opposite the exhaust valve. When open, they form a connection from the combustion chamber to the exhaust port.

Constantly-open throttle valves on a 4-cylin-der engine

When the engine brake* is applied, the constantly-open throttle valves are pneu-matically pressurised on the 4-cylinder en-gine and hydraulically pressurised on the 6-cylinder engine. This opens the valves. At the same time, the engine brake valve on the exhaust gas turbocharger is closed.

The constantly-open throttle valves are not controlled at lower engine speeds (900/1,300 rpm) or at temperatures below 40 °C. When the power unit is being used, these limitations must be taken into ac-count under braking condit ions.

Exhaust brake/ constantly-open throttle valve*

28


General

3

The engine brake* is controlled by the drive control unit (� page 31) or the ADM.

The engine brake* is always disabled be-low 900 rpm to prevent the engine from stalling. The engine brake* is also auto-matically deactivated if the position sensor is triggered (e.g. if the accelerator pedal is depressed).

The engine has a fully electronic control system, which, in addition to the engine and related sensors, also comprises:

� an engine control unit, and

� a drive control unit and/ or other vehi-cle-specific control units or ADM.

Both are interconnected via a CAN (Con-troller Area Network) line which exchanges all the necessary data/ information.

The engine control monitors itself as well as the engine. A safety and emergency run-ning program is selected automatically de-pending on the malfunctions /failures occurring (� page 39).

iIn emergency running mode (constant engine speed), the engine brake* can only be activated in overrun mode at a higher engine speed. The engine brake* is automatically disabled again once the constant engine speed has been reached.

Telligent® engine system

29


General

3

Engine control unit (engine-resident)

The engine control unit is located on the left-hand side of the engine.

Engine control unit

The engine control unit processes data coming from the drive control unit or the ADM, such as the position of the setpoint value sensor (accelerator pedal), the en-gine brake* or engine start/ stop, etc.

This data is evaluated along with data from the sensors on the engine, such as those for:

� charge-air pressure and temperature

� coolant temperature

� fuel temperature

� oil pressure

These parameters are compared with the characterist ic maps and graphs stored in the engine control unit.

Start, duration and amount of injection are calculated from the graphs and the unit pumps are controlled accordingly via the solenoid valves.

Control unit type plate

1 Data record2 Certification no.3 Engine plate4 Equipment code

iAll the information on the control unit type plate is required to obtain a re-placement engine control unit.

The type plate is located on the engine control unit in the upper right-hand cor-ner.

30


General

3

FR (drive control) unit or ADM(appliance-resident)

The engine can be adapted to meet the various application-specific requirements by means of the FR (drive control) unit or adaptation module (ADM).

Drive control unit

The FR (drive control) unit or the ADM unit stores data for specific applications, such as idling speed, maximum working speed and speed limitation.

The FR (drive control) unit and the ADM re-ceive data from the

� operator (position of setpoint value sensor, engine start/ stop)

� engine brake switch*

� other systems (e.g. traction control)

� engine control unit (e.g. o il pressure and coolant temperature)

From this data, the instructions for the MR (engine control) unit are computed and transmitted to it via the CAN line.

The drive control unit and the ADM control various displays, e.g. the electronics warn-ing lamp, the engine brake* and the con-stantly-open throttle valves*.

31


General

3

®
If the Telligent engine system detects a fault, this is stored as a fault code in the control units and can be read using the ap-propriate diagnostic equipment (STAR DIAGNOSIS or Minidiag 2).
In addit ion, the electronics warning lamp is switched on.

Diagnostic socket

Organisational measures

The Operating Instructions and Mainte-nance Booklet must be given to the per-sonnel responsible for operating the engine or carrying out work on the engine, and should be kept in an easily accessible place where the engine is used.

Personnel must be instructed in how to work on the engine using these Operating Instructions. In particular, the safety notes must be explained. This is especially im-portant for personnel who only work on the engine occasionally.

In addition to these Operating Instructions, the country-specific legal and all other binding regulations for accident prevention and protection of the environment must be observed.

iThe DaimlerChrysler diagnostic testers can be connected to the equipment-resident, 14-pin diagnostic socket. Both the malfunction memory and the stored engine data can be read with this equipment. Risk of accident and injury G

Before operating the engine, please read these Operating Instructions and other rele-vant documentation, such as the operating instructions for the vehicle or the machine the engine is installed in.

You could otherwise fail to recognise dan-gers and could injure yourself or others.

32



� Transport and installation

3

Transport

Lifting point, flywheel end Lifting point, timing end

Risk of accident and injury GThe engine can tear loose and cause injury to persons by overturning or falling.

� Only lift the engine by the appropriate lifting points on the engine.

� Only use transport equipment which has been approved for use by DaimlerChrysler.

� Only lift and transport the engine in its installation position.

33



3

Installation

The engine is only designed for installation in accordance with the specifications de-termined in the contract.

The manufacturer of the end product is personally responsible for the complete system of the end product, and in particu-lar for the correct installation and compat-ibility of this engine with the complete system.

Observe the "Correct use" (� page 9) and "Conversion parts and modifications to the engine" (� page 38) sections.

These Operating Instructions contain in-stallation data in the "Technical data" sec-tion.

Should you have any questions, please contact a Mercedes-Benz Service Centre.

iThe engine is fi lled with engine oil at the factory.

34

Safety

4

Safety precautions

Personnel qualifications

Conversion parts and modifications to the engine

Safety/emergency running program

Genuine Mercedes-Benz parts

35

Safety

Safety precautions

4

� Safety precautions
Make sure that the following safety pre-cautions are observed to prevent injury to persons as well as damage to the engine, components and cable harness.
!� Only start the engine with securely

connected batteries.

� Do not disconnect the batteries with the engine running.

� Only start the engine with the rota-tional speed sensor connected.

� Do not use a rapid charger to start the engine.

� Only perform jump-starting with separate batteries.

� Please note that the battery termi-nals must be removed for rapid bat-tery charging. Observe the rapid charger operating instructions.

!� Note that for electric welding work,

the batteries must be disconnected and both connector leads ("+" and "–") securely connected to each other.

� The control unit connectors must only be removed or inserted when the electrical system has been switched off.

� Incorrect polarity of the control unit supply voltage (e.g. through incor-rect battery polarity) can cause ir-reparable damage to the control units.

� Tighten the connections to the fuel-injection system to the specified tightening torque.

� The control units must be removed if temperatures over 80 °C (e.g. in the drying oven) are expected.

!� Only use suitable test leads (e.g.

DaimlerChrysler connection set) for measuring connectors.

� Telephones and two-way radios which are not connected to an ex-ternal aerial can cause malfunc-tions to the vehicle's electronics and could therefore endanger the engine's operating safety.

36

Safety

Personnel qualifications

� Personnel qualifications

4

Engines may only be operated, maintained and repaired by trained personnel instruct-ed and authorised by the operator.

Responsibility for operation, maintenance and repairs must be determined by the op-erator.

The legal minimum age for carrying out the work l isted above must be observed.

Risk of accident and injury GMaintenance and repair work to the engine incorrectly performed can cause engine damage and may lead to personal injury as a consequence.

Maintenance and repair work on the engine may only be carried out by personnel who have undergone the appropriate training.

Always have work on or modifications to the engine carried out at a qualified specialist workshop which has the necessary special-ist knowledge and tools to carry out the work required.


37

Safety

Conversion parts and modifications

4

� Conversion parts and modifications

The warranty does not cover damage aris-ing from tampering with the engine.

Risk of accident GTampering with the engine with the inten-tion to produce modifications to it can im-pair both its correct operation and its safety, leading to personal injury as a consequence.



!Tampering with the fuel-injection sys-tem and engine electronics can affect the engine's performance and emis-sions characteristics. Compliance with the factory settings and legal environ-mental protection conditions can then no longer be guaranteed.

38

Safety

Safety/emergency running programs

� Safety/emergency running programs

4

The engine is equipped with an electronic control system which monitors both the engine and itself (self-diagnostic system).

As soon as the electronic control system has detected and assessed a malfunction, one of the following measures is automati-cally implemented:

� When the engine is in operation, the electronic system warning lamp lights up, indicating a malfunction.

� The fault codes may be shown on a dis-play which is part of the Telligent® engine system (vehicle diagnostic sys-tem).

� The engine switches to the appropriate back-up function for continued (but re-stricted) operation (e.g. constant emer-gency running speed).

Electronic system warning lamp

Risk of accident GIncorrectly performed maintenance and re-pair work on the engine can impair both its correct operation and safety, leading to ac-cidents and personal injury as a conse-quence.



iThe fault codes can be read from the DaimlerChrysler diagnostic testers (STAR DIAGNOSIS or Minidiag 2 test-er), connected to the 14-pin diagnostic socket (equipment-resident).

39

Safety

Genuine Mercedes-Benz parts

4

� Genuine Mercedes-Benz parts
Make sure that the replacement parts are suitable for your vehicle. Parts which lead to a vehicle modification, e.g.:
� a change in the type of vehicle ap-proved in the General Operating Permit

� which could pose a threat to road us-ers, or

� cause a deterioration in exhaust gas emission levels or noise levels,

will result in the invalidation of the General Operating Permit (in many countries). The use of non-approved parts can impair safe-ty.

Additional information about recommend-ed conversion parts and accessories and permissible technical modifications is available from any Mercedes-Benz Service Centre. Always quote the engine plate and type designation when ordering genuine parts. You wil l find the numbers on the en-gine (� page 22) and on the engine data card (� page 24).

Environmental note HTo combine cost-effective repairs with recy-cling, Mercedes-Benz also offers recondi-tioned engines and parts. These are of the same quality and have the same warranty as new parts.

40

Operation

5

Commissioning

Monitoring engine operation

Stopping the engine

Winter operation

Cleaning/protective treatment

Service products

41

Operation

Commissioning

5

� Commissioning

When it leaves the factory, the engine is filled with engine oil in accordance with Sheet 228.5 of the Mercedes-Benz Service Product Guidelines.

These high-quality engine oils assist the running-in process, enabling the first oil change to take place at the usual oil change intervals for normal operation. This eliminates the need for special initial oper-ation oils and the oil change otherwise re-quired.

The extended maintenance intervals can be observed if engine oils in accordance with Sheet 228.5 of the Mercedes-Benz Specifications for Service Products are used.

Oil filler neck

� Check the oil level and add engine oil i f necessary via the filler neck (arrow) up to the maximum mark on the dipstick (� see page 71).

Topping up with coolant

� Coolant composition (� see page 63)

� Fill ing the cooling system (� see page 94).

Preparation

42

Operation

Commissioning

5

Refuelling

Use summer or winter fuel depending on the season. See also "Diesel fuels" (� page 60).

Bleeding the fuel system

The fuel system is bled when the engine is started after refuelling if the fuel system was previously allowed to run dry. Contin-uous bleeding takes place automatically in the filter.

Checking the batteries

Only use batteries which are completely fi lled and have been perfectly maintained. Grease the battery terminals with acid-proof grease (terminal grease).

!Make sure that utmost cleanliness is observed while refuelling and that no water is allowed to enter the tank.

iTo ensure that the fuel system can be bled, the battery must have enough charge when the engine is started.

Risk of burning GThe acid contained in batteries burns skin and eyes on contact.

� Do not allow acid to come into contact with your skin, eyes or clothing.

� Wear suitable protective clothing, as battery acid can burn through normal clothing. In addition, protective gloves and safety goggles should be worn.

� Rinse acid splashes off immediately with clean water and consult a doctor if nec-essary.

Risk of explosion GGases escaping from batteries can explode and injure people.

Therefore, do not allow fire, naked flames, smoking or the creation of sparks in the vi-cinity of batteries.

iThe cable cross-sections are depend-ent on the distance between the bat-tery and the starter motor.

43

Operation

Commissioning

5

Carry out the work listed under "Prepara-tion for commissioning" (� page 42) be-fore operating the engine for the first time.

� Switch on the operating current.

� Start the engine with the setpoint value sensor at idl ing position (e.g. accelera-tor pedal), for instance by operating the starter switch on the equipment or Start button 2 on the engine, (� see page 47).

Start-Stop buttons

1 Stop button2 Start button

Starting the engine for the first time iAs a safety feature, the Tell igent® en-gine system is equipped with a function that only allows the engine to be start-ed with the transmission in neutral.

Risk of burns GThe engine becomes very hot while it is run-ning and remains so for some time after it has stopped. It will cause burns if you touch it.

Before starting any work on the engine, al-low all engine parts to cool down or else wear suitable gloves and items of clothing to protect yourself against hot engine compo-nents.

44

Operation

Commissioning

5
� To check the coolant level:
Leave the engine running at moderate speeds for approximately 5 minutes.

� If the coolant temperature is below 50 °C, check the coolant level again and add coolant if necessary.

Risk of injury GThere is a danger of limbs being caught, en-trapped, crushed or torn off by rotating en-gine parts. Therefore you should:

� Keep a safe distance between yourself and rotating engine parts, including when the engine is being started.

� Wait until all engine parts have come to a standstill before carrying out any work on the engine.

� Wear work clothing which is fastened and close-fitting. Wear a hair net if nec-essary. Remove jewellery such as watches and necklaces.

Risk of scalding GThe cooling system is pressurised. Hot cool-ant can spray out when the cooling system is opened and scald your skin and eyes.

� Only open the cooling system at coolant temperatures below 90 °C.

� Unscrew the sealing cap slowly and re-lease any excess pressure completely before opening the cap fully.

� Wear suitable protective gloves, protec-tive clothing and safety goggles when handling coolant.

Risk of poisoning GThere is a risk of poisoning if coolant is swal-lowed.

� Never swallow coolant.

� Never put coolant into container nor-mally used for beverages.

� Store coolant out of the reach of chil-dren.

��

45

Operation

Commissioning

5

��

Only close the heating system valves once the engine has been running for a brief pe-riod. Top up with coolant if necessary.

� Check the engine for leaks.

� Check the hose fittings, hose clamps and pipe connections on the engine as well as the oil feed and return lines on the exhaust gas turbocharger for leaks and firm seating, and tighten if neces-sary.

� Check the engine oil level approximate-ly 5 minutes after stopping the engine and add oil up to the maximum mark on the dipstick if necessary.

� Check for firm seating of mountings on the engine.

� Check the securing bolts on the ex-haust manifold, engine mountings, coolant pump, starter motor and air compressor for firm seating.

!If a heating system is connected to the cooling system, all heating system valves must be opened while the cool-ing system is being topped up.

Otherwise there might be too little coolant in the cooling system after fill-ing.

46

Operation

Commissioning

5

Starting procedure

In the case of vehicle engines, secure the vehicle to prevent it from rolling away acci-dentally:

� Apply the parking brake.

� Shift the transmission into neutral.

� Place wheel chocks in front of or be-hind the wheels.

� Insert the key into the ignit ion and turn it to the driving position.The following indicator and warning lamps light up:

1 Charge current indicator lamp2 Electronic system warning lamp3 Flame-start system indicator lamp or

grid heater

Start the engine within 30 seconds of the flame-start indicator lamp going out.

Starting the engine

Risk of injury GIf not properly secured, a vehicle might acci-dentally be set in motion when the engine is started, knocking people down or trapping them. Before starting the engine:

� Prevent the vehicle from rolling away by applying the parking brake and, if neces-sary, by placing chocks under the wheels.


iStart ing the engine for the first t ime (� see page 44).

Carry out special measures before starting the engine when it has been stopped for a long period, see the "Cleaning/protective treatment" sec-tion (� page 55).

iAt outside temperatures below –30 °C we recommend preheating the coolant (e.g. using an electric preheating de-vice)

��

47

Operation

Commissioning

5

Start-Stop buttons


� using the starter switch on the equip-ment

� using Start button 2 on the engine.

� Monitor the oil pressure gauge immedi-ately after starting the engine.

At extremely cold temperatures, do not place the cold engine under a full load im-mediately after start ing.

!Keep the engine running at idling speed until an oil pressure reading is dis-played. If no oil pressure is displayed after approximately 10 seconds, switch off the engine. Determine the cause; see the "Oil pressure" section (� page 51).

iIf necessary, break off the starting procedure after a maximum of 20 sec-onds, and then repeat after approxi-mately 1 minute.

The charge current indicator lamp and electronic system warning lamp must go out after the engine has started. If they remain on, there are malfunctions; (� see page 49) and (� page 50).

iThe indicator lamp for the flame-start system lights up for approximately 2 seconds (function check, flame-start system not in operation) to approximate-ly 20 seconds (maximum preglow time) depending on the outside temperature.

If the indicator lamp for the fl ame-start system does not go out after approxi -mately 20 seconds, there is a fault; see the "Telligent® engine system" section (� page 50).

iThe grid heater is controlled by the drive control unit or the ADM control unit. The preglow time lasts for approximately 30 seconds and depends on the temper-ature of the coolant and the charge air. During the preglow time, the indicator lamp lights up and then goes out once the preglow time has finished.

48

Operation


� Monitoring engine operation

5

The charge current indicator lamp must go out after the engine has been started.

Charge current indicator lamp

If the indicator lamp does not go out or lights up when the engine is running, stop the engine and check the poly-V-belt.

Charge current !The poly-V-belt contact surfaces must not be damaged (e.g. torn), oily or glazed.

Do not run the engine without a poly-V-belt since the alternator and coolant pump will not be driven. This will result in engine damage.

49

Operation


5

The electronic system warning lamp must go out after the engine has been started.

Electronic system warning lamp

If the warning lamp does not go out or lights up while the engine is running, there is a fault in the Telligent® engine system.

Each fault is stored in the system with a special fault code. Even temporary faults are stored.

The fault codes may be shown on a display which is part of the Telligent® engine sys-tem (vehicle diagnostic system).

Fault codes can be read using DaimlerChrysler diagnostic equipment (STAR DIAGNOSIS or Minidiag 2-Tester), (� see page 31). If the electronic system warning lamp lights up while the engine is running, read or determine the fault code.

Flame-start system indicator lamp

There is a fault in the flame-start system, if:

� the flame-start system indicator lamp lights up when the engine is running

� the flame-start system indicator lamp does not go out after more than ap-proximately 20 seconds when the en-gine is started

Telligent® engine system Flame-start system*

50

Operation


5

Have the flame-start system checked at a specialist workshop. DaimlerChrysler rec-ommends that you visit a Mercedes-Benz Service Centre for this purpose as it has the necessary specialist knowledge and tools to carry out the work required.

Oil pressure

iThe flame-start system switches off au-tomatically, if:

� the engine is not started within 30 seconds of the flame-start sys-tem indicator lamp going out

� the engine is started while the flame-start system indicator lamp is sti ll lit

� the charge current indicator lamp does not go out when the engine is running

� the engine reaches a temperature at which the flame-start system is no longer needed

Grid heater*

!There is a fault with the grid heater if the indicator lamp flashes.

!Once the operating temperature has been reached, the engine oil pressure must not fall below:

� 2.5 bar at rated speed

� 0.5 bar at idling speed

If the pressure falls below these values, stop the engine and determine the cause.

51

Operation

Stopping the engine

5

� Stopping the engine
� After driving at full power output or at a
high coolant temperature, al low the en-gine to idle without load for one or two minutes.

Start-Stop buttons


� Press Stop button 1 on the engine or on the equipment-resident stopping fa-cility.

!Stop the engine immediately if you ob-serve any of the following signs:

� oil pressure drops or fluctuates considerably

� power and speed drop while the po-sition sensor (accelerator pedal po-sition sensor) stays in the same posit ion

� large amounts of exhaust smoke are emitted from the exhaust

� coolant and oil temperature in-crease very quickly

� unusual noises suddenly occur in the engine or exhaust gas turbo-charger

52

Operation

Winter operation

� Winter operation

5

The following notes should be observed at the start of the cold season:

Fuel

Use cold-resistant diesel fuel (� see page 60).

Engine oil

When changing the engine oil, select an engine oil that is compatible with the SAE class and the ambient temperatures ex-pected during the period of use (� see page 62).

Coolant

Check the coolant's antifreeze protection in good time and increase the antifreeze/corrosion inhibitor concentration if neces-sary (� see page 63).

Risk of fire GThere is an increased risk of fire when han-dling fuels as they are highly flammable.

Avoid fire, naked flames, and sparks and re-frain from smoking when handling fuels.









53

Operation

Winter operation

5

Batteries

Have the batteries serviced and recharged more frequently during the cold months of the year.

Careful maintenance and low power con-sumption will help maintain the full battery charge. Starting capacity is greatly re-duced in cold weather; for example, at -10 °C it is only about 60% of normal ca-pacity. If the engine is not used for a long period of time, store the batteries in a heated place if possible. Ensure good ven-tilation when recharging.

Risk of acid burns GThe acid contained in batteries burns skin and eyes on contact.

� Do not allow acid to come into contact with your skin, eyes or clothing.

� Wear suitable protective clothing, as battery acid can burn through normal clothing. In addition, protective gloves and safety goggles should be worn.



Therefore, do not allow fire, naked flames, and the creation of sparks and do not smoke in the vicinity of batteries.

54

Operation


� Cleaning/protective treatment

5

Cleaning the engine

Risk of poisoning GCare and cleaning agents can be toxic and lead to severe poisoning if swallowed.

� Always keep care and cleaning agent containers closed and out of the reach of children.

� Never store care or cleaning products in foodstuff containers such as bottles so as to avoid confusion with foodstuffs.

� Observe the instructions for using care and cleaning products.

Risk of fire and injury GFuels are highly flammable and can injure your health. I f they are used as cleaning agents, they can cause fires or skin irritation and poisoning.

Never use fuels for cleaning.

Environmental note HObserve the regulations for environmental protection.

Only clean the engine in a washing area de-signed for this purpose. Dispose of empty packaging and used cleaning materials in an environmentally-responsible manner.

!Make sure that water does not enter the intake, ventilation or bleed ducts.

Protect the engine after cleaning. Be careful to protect the belt drive against preservative agents.

iInformation about suitable cleaning and preservative agents is available from any Mercedes-Benz Service Cen-tre.

55

Operation


5

High-pressure cleaners

Observe the manufacturer's operating in-structions.

Information about suitable cleaning and preservative agents is available from any Mercedes-Benz Service Centre.

� Blow out any foreign objects (dust, in-sects, etc.) from the radiator fins using compressed air or remove by spraying water on the rear side of the radiator (against the direction of the cooling air flow).

!Maintain the minimum distance be-tween the high-pressure cleaner nozzle and the object to be cleaned:

� approximately 70 cm for round-spray jets

� approximately 30 cm for 25° flat-spray jets and concentrated-power jets

Keep the water jet constantly moving while cleaning. To avoid damage, do not aim the water jet directly at:

� electrical components

� connectors

� seals or

� hoses

Cleaning the cooling system

Environmental note HCollect used coolant, cleaning solutions and detergents and dispose of them in accord-ance with current local regulations and in an environmentally-responsible manner.

!Only apply moderate pressure when cleaning since the radiator fins could otherwise be damaged.





��

56

Operation


�

5

� Drain off coolant when the engine is cold (� page 95).

� If a heater is attached to the cooling system, open the regulating valves ful-ly.

Degreasing

� Fil l the cooling system with a 5% solu-tion of water and a mild alkaline clean-er, e.g. "P3 Croni" (50 g cleaning agent per litre of water).

� Warm up the engine at moderate en-gine speed up to approximately 80 °C (coolant thermostat starts to open) and allow to run for approximately 5 min-utes longer.

� Switch off the engine and allow to cool to approximately 50 °C.

� Drain off the cleaning solution com-pletely.

� Immediately afterwards, fill the cooling system with clean water, warm up the engine, and drain off the water after 5 more minutes. Then repeat the pro-cedure a second time.

� Fil l the cooling system with new cool-ant (� page 96) and follow the instruc-tions in the "Coolant" section (� page 63).





�

57

Operation


5

The special protection required will de-pend on the length of time the engine is to be out of use as well as the climate of the place where the engine is to be located or stored.

After cleaning the engine, store it in a dry, well-ventilated place as far as possible. If this is not possible, the intervals for carry-ing out regular protective measures must be halved.

It is essential that the engine be protected from direct contact with water (rain/spray water).

If the engine is to be out of use for less than 12 months and the above conditions are met, no corrosion-protection measures need to be taken.

If the engine is to be out of use for more than 12 months and there are excep-tional storage and transport condi-tions, special protective treatment measures are required.

Information is available from any Mercedes-Benz Service Centre. We strong-ly recommend asking for information.

Protective treatment

58

Operation

Service products

� Service products

5

Greases and lubricants must be compati-ble with engine components. For this rea-son, only brands that have been tested and approved by DaimlerChrysler should be used. These are listed in the Mercedes-Benz Specifications for Service Products.

Special lubricant additives are not neces-sary. The warranty entit lement may be re-stricted if special lubricant additives are used.

Risk of poisoning/injury GService products can cause injury or poison-ing if they come into contact with skin or are swallowed.

Observe the prevailing regulations when handling service products and storing and disposing of them. Service products could otherwise endanger people and the environ-ment.

� Always wear appropriate protective clothing and a breathing mask when handling service products. I f possible, avoid inhaling vapours.

� Do not allow service products to come into contact with your skin, eyes or clothing. Clean affected areas of skin with soap and water.

� I f service products do come into contact with your eyes, rinse off thoroughly with clean water and consult a doctor if nec-essary.

� Consult a doctor immediately if a serv-ice product is swallowed.

� Keep service products out of the reach of children.

Risk of fire GThere is an increased risk of fire when han-dling fuels and lubricants as they are highly flammable.

Avoid fire, naked flames, and sparks and re-frain from smoking when handling service products.

iInformation is available from any Mercedes-Benz Service Centre.

Environmental note HDispose of service products as well as parts which come into contact with service prod-ucts, e.g. the filter, in an environmentally-responsible manner.

Observe the legal requirements.

59

Operation

Service products

5

Only use commercially available vehicle diesel fuels (EN 590). Grades such as ma-rine diesel fuel, heating oils, etc. are not permitted.

Fuel additives are not necessary. The war-ranty entit lement may be restricted if fuel additives are used.

If diesel fuels with a sulphur content above 0.3% by weight are used, carry out an oil change at shorter intervals. Observe the information provided in the Maintenance Booklet.

Fill ing the vehicle's fuel tank from drums or canisters may introduce impurities into the fuel system. This can lead to fuel system malfunctions. Therefore, fi lter the fuel when fill ing the tank.

The 900 series engines are suitable for use with FAME fuels in accordance with DIN E 51606. If you do so, you must con-sult a Mercedes-Benz Service Centre to have the exact operating procedures (e.g. maintenance intervals) explained.

Diesel fuels in extremely cold weather

At low outside temperatures, paraffin sep-aration may affect the flow characteristics of diesel fuel.

To prevent operating problems (e.g. as a result of blocked filters), diesel fuel with improved cold flow properties is available on the market in the winter months. Devia-tions may be possible in the transition be-tween the cold and the warm seasons, and in other countries. In Germany, special cold-resistant winter-grade diesel fuels are sold. They ensure reliable operation down to approximately –20 °C. Winter-grade die-sel fuel can normally be used without risk of malfunctioning at the outside tempera-tures expected in the country of sale.

Diesel fuels

60

Operation

Service products

5

If summer diesel fuel or winter diesel fuel with less resistance to low temperatures is used, only add a specific quantity of flow improver or kerosene, depending on the outside temperatures.

Add the flow-improver additive to the die-sel fuel in good time, before paraffin sepa-ration affects the diesel's flow properties. Malfunctions caused by paraffin separa-tion can only be remedied by warming up the entire fuel system.

Do not add additives to especially cold-resistant winter diesel fuels, as the fuel's cold-flow properties could deteriorate.

Flow improvers

The effectiveness of flow improvers cannot be guaranteed with all fuels. Comply with the manufacturer's recommendations. In-formation about approved flow improvers is available from any Mercedes-Benz Serv-ice Centre.

Kerosene

Add as little as possible, depending on out-side temperatures. The addition of 5% by volume of kerosene improves the cold-resistance of diesel fuel by approximately 1 °C. Do not exceed the maximum mixing ratio of 50% kerosene.

Risk of fire and explosion GAdding petrol reduces the flash point for the diesel fuel and increases the risk of fire and explosion.

� Therefore, never add petrol to diesel fuel.

� For this reason, you must avoid fire, na-ked flames and sparks and refrain from smoking when handling these service products.

� Observe the relevant safety regulations.

!If petrol is added, there is a risk of seri-ous engine damage.

Therefore, never add petrol to diesel fuel.

61

Operation

Service products

5

For safety reasons, only mix kerosene with diesel fuel in the fuel tank. Add the kero-sene first, then the diesel fuel. Run the en-gine for a while to ensure that the addit ive reaches all parts of the fuel system.

Engine oil SAE classes

Engine oils are specially tested for suitabil-ity in our engines. Therefore, only use en-gine oil brands approved by Mercedes-Benz. These are listed in the Mercedes-Benz Specifications for Service Products. Observe the information provided in the Maintenance Booklet.

Risk of fire and explosion GAdding kerosene reduces the flash point of the diesel fuel and increases the risk of fire and explosion.

� For this reason, you must avoid fire, na-ked flames and sparks and refrain from smoking when handling these service products.

� Observe the relevant safety regulations.

Engine oils

iThe use of non-approved engine oil brands can restrict the warranty enti-tlement.

62

Operation

Service products

5

If engine oils of a different grade are used, the oil change intervals wil l alter. Informa-tion is available from any Mercedes-Benz Service Centre. Select the SAE class of en-gine oil in accordance with the outside temperatures.

After maintenance work, the engine oil change is entered in the Maintenance Booklet along with the engine oil brand, grade and SAE class.

Only use engine oils of the same grade and SAE class when topping up.

The coolant is a mixture of water and anti-freeze/corrosion inhibitor. The coolant must remain in the cooling system all year round to ensure anti-corrosion protection and to increase the boiling point.

Water

Water without additives is not permitted as a coolant, even if antifreeze properties are not necessary.

The coolant water must satisfy certain re-quirements which are not always fulfilled by drinking water.

If the water is not of sufficient quality, it must be treated.

iIf engine oil of a lower grade is used to top up, the properties of the engine oil are impaired and the engine oil and fil -ter changes must therefore be carried out at shorter intervals.

Coolant





iRenew the coolant every three years, since the level of corrosion protection gradually decreases.

iInformation is available from any Mercedes-Benz Service Centre.

63

Operation

Service products

5

Antifreeze/corrosion inhibitor

To prevent damage to the cooling system:

� Only use approved antifreeze/corro-sion inhibitor. Information is available from any Mercedes-Benz Service Cen-tre.

� When topping up (after coolant loss), make sure that the antifreeze/corro-sion inhibitor concentration is 50% by volume (th is ensures antifreeze protec-tion down to –37 °C).

� Do not use an antifreeze/corrosion in-hibitor concentration of over 55% by volume (maximum antifreeze protec-tion). Above this concentration, anti-freeze protection deteriorates and heat dissipation is less effective.

Coolant mixing ratio:

In exceptional cases, when no antifreeze/corrosion inhibitor is available and/or no antifreeze protection is required (in tropi-cal regions), use an approved coolant additive without antifreeze properties in accordance with Sheet 312.0 of the Mercedes-Benz Specifications for Service Products (e.g. MB corrosion inhibitor A 000 98913 2510 by DaimlerChrysler AG or an approved additive from another man-ufacturer).

Disposal

!If the concentration is too low, there is a risk of engine damage as a result of corrosion/cavitation.

Antifreeze protection down to

–37 °C approxi-mately–45 °C

Water % by vol. 50 45

Antifreeze/cor-rosion inhibitor % by vol.

50 maximum55

!In this case, the coolant must be re-newed every year.

Environmental note HThe coolants mentioned are biodegradable substances. When disposing of used cool-ants, observe the legal requirements and waste water regulations in the country con-cerned.

We recommend that you ask the relevant water authority for advice on the disposal of coolant.

Due to the complex tasks which a modern coolant must perform, improper "recycling" consisting simply of a mechanical pre-clean-ing must be emphatically rejected.

64

Maintenance

6

Maintenance instructions

Overview of work plans

Work plans

65

Maintenance

Maintenance instructions

6

� Maintenance instructions
This section describes all maintenance work which concerns the engine.
The scope of maintenance and frequency of maintenance work depend on the differ-ent operating conditions and are listed in the Maintenance Booklet.

Have the work which is carried out con-firmed in the Maintenance Booklet. This proof of regular maintenance is always re-quired for any warranty claims.

Also observe the maintenance regulations for special accessories.

Risk of accident GBefore any maintenance work or repairs are carried out, please make sure that you read the relevant sections of the technical docu-mentation concerned with servicing and re-pairs, for example:

� Operating Instructions and workshop in-formation

You should also familiarise yourself first with the legal requirements, for example:

� work safety and accident prevention regulations

You could otherwise fail to recognise dan-gers and could injure yourself or others.

Risk of accident GFaulty maintenance work or failure to carry out maintenance work, e.g., not changing the oil filter or not observing the correct maintenance interval, can cause engine damage. Engine damage can lead to an in-creased risk of accident.

For this reason, please observe the instruc-tions on servicing the engine given in these Operating Instructions.

iAll maintenance intervals and mainte-nance work refer to genuine Mercedes-Benz parts and accessories specifically approved for the engine by DaimlerChrysler.

!The engine oil filled at the factory in accordance with Sheet 228.5 of the Mercedes-Benz Specifications for Serv-ice Products must be changed if more than 12 months elapse before the en-gine is operated for the first t ime.

66

Maintenance

Overview of work plans

� Overview of work plans

6

Engine: Oil change and filter replacement

Poly-V-belt: Check condition

Checking for leaks and general condi-tion

Check for points of abrasion and incorrect posit ioning:

Engine

Lines and hoses on the engine

Intake pipe between air cleaner and en-gineCooling and heating system

Checking and correcting the fluid level

If more fluid is lost than can be accounted for by normal consumption, trace the cause and rectify.

Engine cooling system:

Check and correct fluid level and antifreeze/ corrosion inhibitor concen-tration

Check and adjust valve clearance

Fuel prefilter: Clean filter element

Fuel filter: Replace filter

Fuel prefilter with water separator: Replace filter element

Engine brake*: Check condition and setting

Renew coolant

Maintenance service

iChange the engine oil and replace the oil filter at least once a year.

Additional work

iThe valve clearance must be adjusted during the first maintenance service and then during the 3rd, 5th, 7th main-tenance services and so on.

Additional work during every 3rd maintenance service

iRenewal interval depends on the cool-ant additive used (see Mercedes-Benz Specifications for Service Products).

67

Maintenance

Work plans

6

� Work plans

� Visual inspection of the engine for signs of leakage.

Sealing points which are slightly damp are harmless.

� Make a visual inspection of l ines and hoses. Also make a listening check for:

� leaks

� check for undamaged condit ion

� chafe-free routing and

� correct mounting

Engine: Checking for leaks and general condition

!Remedy more significant leaks involv-ing constant oil loss immediately.

Lines and hoses on the engine: Checking for leaks and general condition

Risk of burns GThe engine is very hot when it is running and also for some time after it has been swit-ched off. It may cause burns if you touch it.

Before starting any work on the engine, al-low all engine parts to cool down or else wear suitable gloves and items of clothing to protect yourself against hot engine compo-nents.

Risk of injury GThere is a danger of limbs being caught, en-trapped, crushed or torn off by rotating en-gine parts. Therefore you should:

� Keep a safe distance between yourself and rotating engine parts, including when the engine is being started.

� Wait until all engine parts have come to a standstill before carrying out any work on the engine.

� Wear work clothing which is fastened and close-fitting. Wear a hair net if nec-essary. Remove jewellery such as watches and necklaces.

68

Maintenance

Work plans

6
� Remove the oil filter cap using the
socket spanner insert (WAF 36). Allow oil to drain from the filter housing.

� Unscrew cap 1 and oil filter element 3 and remove element 3 from the cap by pressing the lower edge on the sides.

Oil filter cap

Engine: Oil change and filter replacement

iOnly change engine oil when the engine is at normal operating temperature.

Risk of scalding GHot engine oil spraying out can scald your skin and eyes.

Wear suitable protective gloves, protective clothing and eye protection.

!Make sure that no foreign objects enter the fi lter housing. Never wipe the fi lter housing out.

69

Maintenance

Work plans

6
Cap with oil filter element
1 Cap2 Sealing ring3 Oil fi lter element

� Replace the sealing ring on cap 2.

� Insert new filter element in the cap and clip it into place by pressing on it.

� Screw the cap on the oil fi lter housing and tighten itTightening torque: 25 Nm.

Extracting and draining the engine oil

Extraction:

� Extract the engine oil through the dip-stick guide pipe. To do this, pull out the dipstick and insert the scavenging de-vice sealed with an O-ring into the guide pipe.

Dipstick guide pipe

!Observe the operating instructions for the engine oil scavenging device.

70

Maintenance

Work plans

6

Draining:

� Place a suitable collecting receptacle under the drain plug on the underside of the oil sump.

� Unscrew the drain plug carefully and al-low the oil to drain out.

Oil drain plug

Renewing:

� Screw the drain plug back in with a new sealing ring and tighten.Tightening torque: M20 x 1.5 – 60 NmM26 x 1.5 – 85 Nm

� Add new engine oil into the engine via the oil filler neck up to the maximum mark on the dipstick.

Oil filler neck

Environmental note HDispose of engine oil and filters in accord-ance with the regulations in force at the place of use of the engine.

��

71

Maintenance

Work plans

6

��
� Start the engine with the setpoint value sensor in the idling position. Monitor the oil pressure gauge.
� Check the fi lter and drain plug for leaks.

� Stop the engine. Check the oil level af-ter approximately 5 minutes. Top up oil to the maximum mark on the dipstick if necessary.

!Keep the engine running at idl ing speed until an oil pressure reading is dis-played. If no oil pressure is displayed after approximately 10 seconds, switch off the engine and establish the cause.

72

Maintenance

Work plans

6

Layout of cylinders and valves

Special tools

Rotation device: 904 589 04 63 00

Valve clearance:

Adjusting the valve clearance

= inlet valve

= exhaust valve

= flywheel endX

Inlet valves = 0.40 mm

Exhaust valve = 0.60 mm

iAdjust the valve clearance when the engine is cold (at least 30 minutes after the engine was stopped, even if it was only operated for a brief period).

Clean very dirty cylinder head covers before removing.

Risk of injury GIf not properly secured, a vehicle might acci-dentally be set in motion, knocking people down or trapping them and otherwise caus-ing an accident and injuring you or others.

� Always secure the vehicle against rolling away by applying the parking brake and, if necessary, by placing chocks under the wheels.


� Only turn the engine over using the rota-tion device provided for this purpose.

73

Maintenance

Work plans

6

Removing and fitting the cylinder head cover

1 Charge-air manifold2 Cylinder head cover 3 Allen bolt4 Sealing washer5 Cover seal6 Engine breather hose

Removing:

� Remove engine breather hose 6 from the cylinder head cover.

� Unscrew Allen bolt 3 from the cylin-der head cover together with sealing washers 4.

� Remove cylinder head cover 2.

Fitting:

� Clean the cylinder head and the cylin-der head cover sealing surfaces.

� Check the gasket between the cylinder head cover and charge-air manifold 1 and replace if necessary.

� Always replace the gasket between the cylinder head cover and the cylinder head.

� Position the cylinder head cover.

� Fit Allen bolts 3 with new sealing washers 4 and tightenTightening torque: 30 Nm.

Flywheel housing inspection hole

� Fit rotation device (904 589 04 63 00) on the flywheel housing inspection hole.

74

Maintenance

Work plans

6

Adjusting the valve clearance

I – inlet valve

E – exhaust valve

Adjust all valve clearances in 2 crankshaft posit ions.

� Use the rotation device to turn the crankshaft until no. 4 or 6 cylinder is at overlap TDC (no. 1 cylinder at ignition TDC). Then turn no. 1 cylinder to over-lap TDC (no. 4 or 6 cylinder at ignition TDC).

� Check the valves in accordance with the above table and adjust.

Engine Crankshaft position Cylinder/ valves to be adjusted

1 2 3 4 5 6

OM 904/ 924 LA 4th cylinder valve overlap I/ E I E -1st cylinder valve overlap – E I I /E

OM 906/ 926 LA 6th cylinder valve overlap I/ E I E I E -1st cylinder valve overlap – E I E I I/ E

75

Maintenance

Work plans

6

Checking and adjusting the valve clearance

1 Adjustment screw2 Counternut

� Measure the valve clearance between the rocker arm and valve stem (exhaust valve) or valve bridge (inlet valve) with a feeler gauge (arrow). It must be possible to pull the feeler gauge through with only light resist-ance.

� Slacken counternut 2 to adjust the valve clearance. Adjust the valve clear-ance by turning adjustment screw 1.

� Retighten the counternut. Tightening torque: 25 Nm.

� Check the valve clearance again and readjust if necessary.

Concluding work

� Refit the cylinder head cover (� see page 74).

� Remove the rotation device from the flywheel housing inspection hole.

76

Maintenance

Work plans

6

Fuel prefilter

1 Cap2 Filter element3 Sealing ring

� Open the tank cap to remove excess pressure in the fuel tank.

� Clean the outside of the fuel prefilter and cover any hoses /lines under the prefi lter.

� Unscrew cap 1 and pull it out of the filter housing together with fi lter element 2.

� Clean cap 1 and fi lter element 2.

Replace the filter element if it is very dirty or damaged.

� Check sealing ring 3 for the cap and replace if necessary.

� Insert the filter element in the cap and screw the cap onto the filter housing.Tightening torque: 25 Nm.

Fuel prefilter: Cleaning the filter element Risk of fire G

There is an increased risk of fire when han-dling fuels as they are highly flammable.

Avoid fire, naked flames and sparks and re-frain from smoking when handling fuels.

Environmental note HDispose of used filter elements and fuel res-idue in accordance with current local regula-tions.

77

Maintenance

Work plans

6

Fuel prefilter with heated water separator*

1 Hand pump2 Filter housing3 Water separator (heated)4 Water drain valve

� Open the drain valve and loosen the vent screw. Collect the fuel/ water mixture from the fi lter element in a suitable receptacle.

� Remove the heater connector.

� Unscrew the filter element.

� Remove the separator vessel from the filter element and clean or replace as necessary.

� Refit in the reverse order. Use new sealing rings when fitting.

Fuel prefilter with heated water separator*: Replacing the filter element

Risk of fire GThere is an increased risk of fire when han-dling fuels as they are highly flammable.

Avoid fire, naked flames and sparks and re-frain from smoking when handling fuels.

Environmental note HDispose of used filter elements and fuel res-idue in accordance with current local regula-tions.

��

78

Maintenance

Work plans

��

6

� Close the drain valve and fi ll the pre-filter using the fuel hand pump. Then close the vent screw.

� Start the engine and bleed the fuel sys-tem.

� Check the pre-filter for leaks.

!Screw the fi lter element onto the filter head tightly by hand.

iLeave the engine running for approxi-mately 1 minute. The fuel system bleeds automatically.

79

Maintenance

Work plans

6

Fuel filter

1 Cap2 Filter housing

� Open the tank cap to prevent excess pressure in the fuel tank.

� Unscrew fuel fi lter cap 1 with the socket spanner insert (WAF 36).

� Pull cap 1 and filter element slightly out of filter housing 2. Allow fuel to flow out.

1 Cap2 Sealing ring3 Filter element4 Dirt trap5 Filter housing

Replacing the fuel filter elementRisk of fire GThere is an increased risk of fire when han-dling fuels as they are highly flammable.

Avoid fire, naked flames and the creation of sparks refrain from smoking when handling fuels.

��

80

Maintenance

Work plans

��

6

� Remove the cap and fi lter element. Un-clip fi lter element 3 by pressing the lower edge of the filter element on the sides.

� Pull dirt trap 4 out of the filter housing by the tabs.

� Clean cap 1 and dirt trap 4.

� Replace sealing ring 2.

� Clip new filter element 3 into cap 1.

� Lightly grease sealing ring 2 and the filter element seals.

� Insert dirt trap 4 into filter housing 5; observe the correct installation po-sition.

� Screw on cap and fi lter element and tighten.Tightening torque: 25 Nm.

� Start the engine and bleed the fuel sys-tem.

� Check the fuel fi lter for leaks with the engine running.

!Neither dirt nor water should enter the filter housing; do not empty dirt trap 4 into the filter housing.

iIf the level of the diesel fuel in the tank is higher than the level of the engine, the feed line must be closed when re-placing the filter.

The diesel fuel could flow out.

iLeave the engine running for approxi-mately 1 minute. The fuel system bleeds automatically.

iTo ensure the fuel system can be bled, the battery must have enough charge when the engine is started, since the fuel system must fill up with fuel first.

81

Maintenance

Work plans

6

� Check the rubber sleeves, intake pipe and connection hoses for damage and leaks.

� Check the hose clamps, flanged joints and intake manifold for firm seating.

Intake pipe between air cleaner and engine: Checking for leaks and general condition

82

Maintenance

Work plans

6
Special tools
Rotation device: 904 589 04 63 00

� Fit the rotation device to the flywheel housing inspection hole.

� Make a chalk mark on the poly-V-belt.

Check the poly-V-belt for damage in sec-tions; rotate the engine and poly-V-belt a little at a time

Flywheel housing inspection hole

� rotate further using the rotation device unti l the chalk mark is reached again.

� Remove the rotation device.

Poly-V-belt: Checking the condition

Risk of injury GFaulty poly-V-belts may tear and parts or all of the belt may be thrown off, thereby caus-ing injury to persons.

� Always observe the specified mainte-nance intervals for poly-V-belts.

� If damage is detected, replace the poly-V-belt concerned immediately.

iReplace the poly-V-belt if one of the damage patterns shown on the next page is detected. For information on in-stalling and removing the poly-V-belt (� see page 86).

83

Maintenance

Work plans

6

84

Maintenance

Work plans

6

Damage patterns

1 Condition as new (as reference: trape-zoidal ribs)

2 One-sided wear: wedge-shaped ribs3 Cord visible in the base of the ribs4 Ribs split5 Transverse cracks in several ribs6 Rubber lumps in the base of the belt7 Deposits of dirt or stones8 Rib detached from the base of the belt9 Cord torn out to the sidea Outer cord frayedb Transverse cracks on the back of the

beltc Transverse cracks in several ribs

85

Maintenance

Work plans

6

Removing and installing the poly-V-belt

Spanner with extension in the tensioning device

1 Tensioning pulley2 Spanner

� Attach spanner 2 with the 17 mm socket to the hexagon bolt of tension-ing pulley 1.

� Swing the tensioning pulley upwards and remove the poly-V-belt.

� Swing back the tensioning device.

� Check that the tensioning device and belt pulley are in perfect condition (e.g. check for worn bearings on the ten-sioning device, tensioning pulley and deflection pulleys as well as wear on belt pulleys); replace parts if necessary.

� Lay the poly-V-belt (new) on all belt pul-leys, except for the tensioning pulley (see illustrations for poly-V-belt rout-ing).

� Swing the tensioning pulley upwards using the lever, insert the poly-V-belt and swing back the tensioning pulley.

� Remove the spanner and check for cor-rect seating of the poly-V-belt on the belt pulley.

Risk of injury GThe tensioning device is spring-tensioned. When it is loosened or tightened, there is a risk of injury from hands or fingers being crushed or trapped in pretensioned parts.

� Make sure that the tool is handled cor-rectly.

� Keep your fingers out of the area be-tween the belt pulley and the poly-V-belt when fitting or dismantling the poly-V-belt.

� Wear work gloves when working on the tensioner.

86

Maintenance

Work plans

6

Routing of the poly-V-belt (engine without refrigerant compressor)

1 Alternator2 Coolant pump3 Tensioning pulley4 Crankshaft

Routing of the poly-V-belt (engine with refrigerant compressor)

1 Alternator2 Coolant pump3 Tensioning pulley4 Refrigerant compressor5 Deflection and guide pulley6 Crankshaft

87

Maintenance

Work plans

6

Throttle valve lever in rest position

1 Throttle valve lever2 Retainer

Throttle valve lever in working position

1 Throttle valve lever2 Retainer

Checking the condition

� Remove the wire circlip from the ball cup on the engine cylinder.

� Force the ball cup off the ball neck of throttle valve lever 1.

� Check the engine brake cylinder, ball neck and ball cup, and the throttle valve shaft for wear.

� Check the firm seating of the throttle valve lever on the throttle valve shaft. Tighten screws if necessary.

� Grease the ball cup with the grease specified.

� Push the ball cup back onto the ball neck.

� Fit the wire circlip.

Engine brake: Checking the condition and setting

88

Maintenance

Work plans

6

Checking the adjustment

iThrottle valve lever 1 must lie against bracket 2 in the operating position (cylinder extended) when the engine brake is operated.

When the engine brake cylinder (with the cylinder retracted) is in the rest po-sition, the throttle valve lever must also lie against the bracket; the pre-tension of the engine brake cylinder return spring is then sufficient.

Check the position of the throttle valve shaft: the notches must be horizontal when the engine brake is in the rest po-sition (� page 88, i llustration on the left-hand side). The notches must be vertical in the working position (� page 88, illustration on the right-hand side).

89

Maintenance

Work plans

6

� Open the engine cooling system radia-tor cap slowly. Relieve excess pres-sure.

� Check the antifreeze/ corrosion inhibi-tor using testing device. The correct concentration of 50% by volume antifreeze/corrosion inhibitor in the coolant is indicated when there is anti-freeze protection down to –37 °C. If less antifreeze protection is displayed, correct the mixing ratio.

Engine cooling system: Checking and correcting the fluid level and the antifreeze/ corrosion inhibitor







� Never put coolant into containers nor-mally used for beverages.


!Only use service products approved by DaimlerChrysler, (� see page 63).

iOnly check and correct the coolant lev-el when the coolant temperature is below 50 °C. Check the antifreeze/corrosion inhibitor before correcting the coolant level. Only use prepared coolant with 50% by volume anti-freeze/corrosion inhibitor for topping up.

90

Maintenance

Work plans

6
� Check the coolant level.
The cooling system is correctly fi lled if the coolant reaches the mark in the filler neck.

The "Engine cooling system: Checking and correcting the fluid level and antifreeze/corrosion inhibitor" work item must have already been carried out.

� Carry out a visual inspection of the ra-diator for leaks and undamaged condi-tion.

� Check the radiator for external dirt. The fins must not be dirty.

� Check that all l ines and hoses are un-damaged, that they are routed to avoid chafing and that they are secured in ac-cordance with the regulations.

!If the concentration is too low, there is a risk of engine damage as a result of corrosion/cavitation in the cooling system.

!Avoid concentrations of more than 55% by volume antifreeze/corrosion inhibi-tor, otherwise maximum antifreeze pro-tection down to –45 °C will not be achieved. If the concentration is higher, heat dissipation and antifreeze protec-tion deteriorate.

Cooling and heating system: Checking for leaks and general condition

!If damage/faults are found, repair the radiator or replace it .

91

Maintenance

Work plans

6
�
Special tool:

Pressure tester 001 589 83 21 00

� On heating systems: Open the regulat-ing valves and shutoff valves.

� Remove the coolant expansion tank cap.

� Fit the testing equipment.

Pressure tester special tool









�

92

Maintenance

Work plans

��

6

� Connect the compressed-air hose with the tyre inflator connection to the valve and build up a test pressure equal to the cooling system opening pressure.

The cooling system opening pressure can be seen on the code on the cap or pressure relief valve.

Example: Code 70 = 0.7 bar pressure.

iA pressure relief valve is integrated in the testing equipment so that a pres-sure of 1.2 bar cannot be exceeded.

93

Maintenance

Work plans

6

Renewing coolant









!Only use antifreeze/ corrosion inhibitor approved by Mercedes-Benz (� see page 59).

iBefore renewing the coolant, check the cooling and heating system for leaks and condition. Have the coolant renew-al confirmed in the Maintenance Book-let.

94

Maintenance

Work plans

6

Draining coolant

� Open the engine cooling system radia-tor cap slowly. Let off excess pressure and remove the radiator cap.

� On heating systems: Open the heating temperature selector (regulating valve).

Coolant drain plug

� Place the drain hose on the coolant drain plug on the engine (arrow).

� Loosen the drain plug (1 to 2 turns)The coolant flows out.

Risk of scalding GHot coolant will scald your skin and eyes.

� Only carry out work on the cooling sys-tem at coolant temperatures below 50 °C.


iThere are additional drain plugs on the radiator.

iFirst cover the lines, etc. beneath the drain plugs and place a receptacle suit-able for the volume of coolant.

95

Maintenance

Work plans

6

� Clear blocked drain openings from de-posits.

� Retighten the coolant drain plug on the engine.

� Pull off the drain hose.

� Fit additional drain plugs (without hose connections) with new seals and screw tight.

Adding coolant

� Start the engine and allow it to run at different speeds for approximately 1 minute.

� Add coolant in the specified ratio unti l it reaches the lower edge of the filler neck.

� Switch off the engine and close the cooling system again.

Environmental note HDispose of used coolant in accordance with prevailing local regulations (� see page 64).

iFor further information, see the vehicle manufacturer's operating instructions.

96

Practical advice

7

Malfunctions, causes and solutions

Jump-starting

97

Practical advice


7

� Malfunctions, causes and solutions
Besides careful operation and mainte-nance of the engine, it is important that malfunctions are remedied in good t ime. Further information on the measures listed under "Solution" can be found in the "Main-tenance" or "Tests and other work for rem-edying problems" section.
You can rectify certain faults yourself (� page 99).

Always have faults that you cannot remedy yourself rectified at a qualified specialist workshop.

DaimlerChrysler recommends that you vis-it a Mercedes-Benz Service Centre for this purpose as it has the necessary specialist knowledge and tools to carry out the work required. In particular, work relevant to safety or on safety-related systems must be carried out at a qualified specialist workshop.

Risk of accident and injury GIncorrect maintenance and repair work to the engine can cause engine damage and may cause personal injury as a conse-quence.

Maintenance and repair work on the engine may only be carried out by personnel who have undergone the appropriate training.

Always have work on or modifications to the engine carried out at a qualified technical workshop which has the necessary special-ist knowledge and tools to carry out the work required.


98

Practical advice


7

General troubleshooting

Malfunction Cause Solution

Starter pinion does not turn or turns too slowly

Battery is not sufficiently charged � Charge the battery

Connecting cable to the starter motor is loose

� Tighten the cable on the terminal. If necessary, solder on a new terminal.

Starter motor solenoid switch malfunction � Have it checked by specialists

Engine does not start or stops again imme-diately

Fuel tank empty � Refuel

Fuel fi lter blocked � Clean or replace the filter element (� page 80)

Fuel line, pre-cleaner or screen in the fuel tank blocked

� Clean and bleed the system

Fuel system or filter leaking � Seal

Fuel not resistant to cold � Clean the pre-fi lter (� page 78)

� Replace fuel filter

� Use winter fuel (� page 60)

Outside temperature too low � Observe measures for winter operation (� page 53)

99

Practical advice


7


Engine starts badly Fuel temperature too high or sensor mal-function

� Replace fuel temperature sensor; con-sult a qualified specialist workshop

Engine control unit malfunction � Read engine control unit malfunction memory, consult a qualified specialist workshop

Leakages or pressure too low in the low-pressure fuel circuit

� Test for leaks (visual inspection); have pressure tested at a qualified specialist workshop

Engine stops unexpectedly Engine control unit malfunction (total fail-ure)

� Consult a qualified specialist workshop

Electrical system interrupted; short circuit in cabling or in Stop button; engine control unit malfunction


Leakages or pressure too low in the low-pressure fuel circuit or fuel delivery pump drive defective


100

Practical advice


7


Engine in emergency running mode:Constant speed 1,300 rpm

Engine control unit or drive control unit malfunction

� Read malfunction memory in control units; consult a qualified specialist workshop

Engine surges, vibrates or runs irregularly Crankshaft position sensor or TDC sensor (camshaft angle sensor) polarity reversed

� Remove each sensor; sensor polarity is reversed if engine runs better (emer-gency running engine speed) – reverse polarity

� Consult a qualified special ist workshop

Poor engine output (lack of power) Charge-air pressure sensor malfunction � Check with DaimlerChrysler diagnostic tester; replace if necessary; consult a qualified specialist workshop

Charge-air temperature too high or temperature sensor malfunction

� Check temperature sensor; replace i f necessary; consult a qual ified specialist workshop

Fuel temperature too low � Check temperature sensor; replace if necessary, check fan speed cut-in point; consult a qualified specialist workshop

Coolant temperature too high � Check temperature sensor; replace if necessary; check fan speed cut-in point; consult a qualified specialist workshop

101

Practical advice


7


Poor engine output (lack of power) Engine brake valve* defective � Carry out function or visual inspection

Fault in the fuel system (blocked, leaking) � Carry out visual inspection for leaks; consult a qualified specialist workshop

Engine control or drive control module malfunction

� Read control unit malfunction memory; consult a qualified specialist workshop

Tractive force interruption Loose contacts in the electrical supply � Check battery terminal clamps and connector on engine control unit for firm seating and corrosion

Leakages or pressure too low in the low-pressure fuel circuit


Poor engine braking power Drive control unit malfunction � Read drive control unit malfunction memory; consult a qualified specialist workshop

Constantly-open throttle valve* defective � Check control; consult a qualified spe-cialist workshop

Engine brake flap* defective � Carry out a function/visual inspection; consult a qualified specialist workshop

102

Practical advice


7


Fuel consumption too high Fuel temperature too high or sensor mal-function

� Replace fuel temperature sensor; con-sult a qualified specialist workshop

Turbocharger leaking on pressure (deliv-ery) side

� Carry out a test for leaks; consult a qualified specialist workshop

Connection points (unit pump – line and in-jectors) defective or leaking

� Set pumps using STAR DIAGNOSIS or Minidiag 2; consult a qualified special-ist workshop

Engine cut-off too early (maximum revs cannot be reached)

Drive control unit or ADM control unit de-fective or incorrectly programmed


Engine gets too hot (according to coolant temperature gauge)

Coolant temperature sensor malfunction � Replace sensor

Insufficient coolant or cooling system not fully bled

� Top up, bleed (� page 96)

Poly-V-belt damaged � see Replacing the poly-V-belt (� page 86)

Fan does not switch on correctly � Consult a qualified specialist workshop

Radiator dirty on inside or choked with limescale; radiator very dirty on outside

� Clean or remove l imescale

Thermostat malfunction � Check, replace if necessary; consult a qualified specialist workshop

103

Practical advice


7


Charge current indicator lamp does not light up while the vehicle is stationary

Bulb malfunction or supply line broken � Replace bulb or repair break

Charge current indicator lamp lights up when the engine is running

Poly-V-belt too slack � Check belt tension; replace tensioning pulley if necessary

Poly-V-belt torn � Replace the poly-V-belt (� page 86)

Alternator or regulator malfunction � Check; consult a qualified specialist workshop

Engine emits black smoke Charge-air sensor, coolant sensor or fuel temperature sensor defective

� Check with DaimlerChrysler diagnostic tester; consult a qualified specialist workshop

Injector defective � Consult a qualified specialist workshop

Exhaust gas turbocharger or charge-air pipe defective, air cleaner dirty

� Carry out visual inspection; consult a qualified specialist workshop

Constantly-open throttle valve defective � Consult a qualified specialist workshop

Exhaust fumes are blue Oil level in the engine too high; engine oil entering combustion chamber

� Correct oil level; have it checked at a qualified specialist workshop

104

Practical advice


7


Exhaust fumes are white Cylinder head or cylinder head gasket leaking; coolant entering the combustion chamber

� Locate damaged cylinder using pres-sure loss test; consult a qualified spe-cialist workshop

Engine "knocks" Combustion malfunction � Consult a qualified specialist workshop

Knocking noise from the bearings Damage to bearings � Consult a qualified specialist workshop

Abnormal noises Leakage in intake pipe and exhaust pipe causes whistling noise

� Remedy leakage; replace seals if nec-essary

Turbine or compressor wheel scrapes on the housing; foreign object in the compres-sor or turbine; seized bearing in rotating parts

� Have the exhaust gas turbocharger re-placed at a qualified specialist work-shop

105

Practical advice

Jump-starting

7

� Jump-starting
If the battery is discharged, the engine can be started using jump leads and a donor battery.
� Connect the positive terminals first and then the negative battery terminals.

� Start the engine (� see page 47) and allow to run for a short while.

� Remove the jump leads in the reverse order.

Risk of burning GThe acid contained in batteries burns skin and eyes on contact.

� Avoid contact of acid with your skin, eyes or clothing.

� Wear suitable protective clothing, as battery acid can burn through normal clothing, and also wear protective gloves and safety goggles.



Therefore, avoid fire, naked flames and sparks and refrain from smoking in the vicin-ity of batteries.

!Make sure that the donor battery and the starter battery have the same nom-inal voltage. Otherwise a battery could be irreparably damaged.

Do not place any metal parts on the batteries. There is a risk of short cir-cuit.

Only use insulated jump leads (cable cross section approximately 70 mm2) and insulated terminal clamps. There is a risk of short circuit.

A discharged battery can freeze at about –10 °C; it must have thawed out before jump-start ing.

!When jump-starting the engine, the maximum on-board voltage of 28 V must not be exceeded (as this would cause electronic damage to the control part).

106

Technical data

8

Engine data

Test values and adjustment values

Tightening torques

107

Technical data

Engine data

8

� Engine data
Dimensions in mm:
(Standard version, other versions on re-quest)

Illustrated: OM 904/924 LA Illustrated: OM 904/924 LA

OM 904 LA

OM 924 LA

A = Engine length 830 mm

B = Engine width .645 mm

C = Engine height 925 mm

OM 906 LA

OM 926 LA

A = Engine length 1,078 mm

B = Engine width .645 mm

C = Engine height 940 mm

108

Technical data

Engine data

8

Weights

General data

OM 904 LA

OM 924 LA

OM 906 LA

OM 926 LA

Engine, dry 395 kg 530 kg

Engine, wet 420 kg 573 kg

Type In-line engine with exhaust gas turbocharger and intercooler

Type of cooling system Forced circulation cooling

Combustion principle 4-stroke diesel direct injection

Number of cylindersOM 904 LA/ OM 924 LA:OM 906 LA/ OM 926 LA:

46

Cylinder boreOM 904 LA/ OM 906 LAOM 924 LA/ OM 926 LA

102 mm106 mm

Piston strokeOM 904 LA/ OM 906 LAOM 924 LA/ OM 926 LA

130 mm136 mm

109

Technical data

Engine data

8
General data continued
DisplacementOM 904 LA/ OM 924 LA:OM 906 LA/ OM 926 LA:

4,250 cm3 /4,800 cm3

6,370 cm3 /7,200 cm3

Direction of rotation of engine viewed from flywheel Anti-clockwise

Type of start ing Electric

Coolant capacity of engine without intercoolerOM 904 LA/ OM 924 LA:OM 906 LA/ OM 926 LA:

8.5 l12.5 l

Engine oil capacity including oil filterOM 904 LA/ OM 924 LA:OM 906 LA/ OM 926 LA:

min. 13 l; max. 16 lmin. 24 l; max. 29 l

110

Technical data

Engine data

8

Data: Starter motor, battery and alter-nator (standard)

Starter motor

Voltage 24 V

Output 4.0 kW

Battery (not in scope of delivery)

Voltage 24 V

Cold test current in accordance with DIN 72311 max. 450 A

Cold start ability without jump-starting and 75% battery charge down to max. –20 °C

Alternator

Voltage 28 V

Current rating 80 A

111

Technical data

Test values and adjustment values

8

� Test values and adjustment values
Engine oil pressure (min)
Valve clearance

at idling speed ≥ 0.5 bar

at rated speed ≥ 2.5 bar

Inlet valve 0.4 mm

Exhaust valve 0.6 mm

112

Technical data

Tightening torques

� Tightening torques

8

iAll threads on mechanical parts and re-lated contact surfaces must be clean and smooth and lubricated with engine oil; other lubricants require significant-ly different t ightening torques.

Designation Nm

Engine block

Cylinder head cover to cylinder head bolt 30

Oil sump bolt to cylinder crankcase 25

Poly-V-belt tensioning device to cylinder crankcase/ to hydraulic pump retainer/to support 50

Fuel/injection system

Injection line to unit pump pressure pipe connection 35

Banjo bolts for fuel l ines 40

Cap to fuel filter housing 25

Starter motor/alternator

Starter motor to t iming case 50

Alternator support to cylinder crankcase 100

113

Technical data

Tightening torques

8

Designation Nm

Alternator to support 50

Alternator to retainer 65

Oil circuit

Oil drain plug in oil sump M20 x 1.5 threadM26 x 1.5 thread

6585

Alternator retainer to oil fi lter 40

Oil fi lter housing to cylinder crankcase 25

Oil fi lter housing support to cylinder crankcase 25

Oil fi lter cap to oil filter housing 25

Pressure sensor to oil filter housing 25

Valve adjustment

Counternut on rocker arm set screw 25

Cooling circuit

Coolant line with thermostat valve to coolant pump 25

Coolant pump to cylinder crankcase 25

Belt pulley to coolant pump hub 25

114

Technical terms

9

ADMControl module as interface between the engine and the vehicle electronics.

Belt driveDrive connection from the engine to the engine assemblies, such as the al-ternator, coolant pump or refrigerant compressor.

CAN (Controller Area Network)Serial data transfer system which net-works the vehicle's electronic systems and allows an organised mutual data exchange. At the same time the number of components required is low-er. This reduction of potential malfunc-tion sources improves reliability and maintenance friendliness.

Constantly-open throttle valveValve fitted in the cylinder head in con-junction with throttle valve brake or Turbobrake*. When the engine brake is operated, the constantly-open throttle valve causes a reduction in the cylinder pressure during the working stroke.

Control unitPart of the electronic system which controls the engine or transmission functions, for example.

Emergency running programSpecial program in the Tell igent® en-gine system which allows limited engine operation if electronic compo-nents have failed.

Engine oil viscosityMeasurement of the internal friction (viscosity) of an oil at a defined temper-ature. The viscosity is better the higher the temperature the oil can withstand without becoming too thin, or the lower the temperature the oil can withstand without becoming too thick.

Engine plateNumber specified by the manufacturer and marked on the cylinder head to clearly identify each engine.

Exhaust brakealso throttle valve brake. Works by closing the exhaust pipe.

FAME fuels(Fatty Acid Methyl Ester) FAME fuels are bio-diesel fuels based on fatty acid methyl esters.

Flame-start systemThis is a cold-start aid for the engine. It can be used to preheat the charge air using fuel combustion.

FR(Drive control) control unit. The drive control is a monitored electronic sys-tem and is connected to the engine control via the CAN bus. The FR is per-manently installed in the driver's cab. It controls vehicle-relevant functions and switches on the engine control via CAN bus commands, e.g. engine torque re-quest via accelerator pedal position.

Grid heaterThis is a cold-start aid for the engine. It can be used to preheat the charge air using a heater coil.

115

Technical terms

9

Minidiag 2DaimlerChrysler AG electronic diag-nostic tool for reading faults and pa-rameters on commercial vehicles.

MR(Engine control) control unit. Engine control is a monitored electronic sys-tem which forms part of the Telligent® engine system. It controls the engine functions, such as the engine idling speed and exchanges data with the drive control.

OMEngine name, abbreviation for oil en-gine = diesel engine.

SensorElectronic component which converts certain parameters (e.g. oil tempera-ture, engine speed and others) into electrical values for use in the engine control unit.

STAR DIAGNOSISDaimlerChrysler AG electronic diag-nostic system

TDCTop dead centre; term for the upper po-sition of the piston in the cylinder.

Telligent ® engine systemMercedes-Benz electronic engine con-trol. Controls fuel injection period and quantity depending on the current op-erating conditions and driver's re-quests.

Tightening torque (Nm)Product of force and lever arm length with which bolted connections, e.g. cylinder head bolts, are tightened. (Nm = Newton metres)

116

Index

9

AAdaptation module . . . . . . . . . . . . . . 31Adjusting the valve clearance . . 73, 75ADM . . . . . . . . . . . . . . . . . . . . . . . . . . . 31Alternator . . . . . . . . . . . . . . . . . . . . . 111Antifreeze/corrosion inhibitor . . . . . 64

BBattery . . . . . . . . . . . . . . . . 43, 106, 111

CCharge current . . . . . . . . . . . . . . . . . . 49Commissioning . . . . . . . . . . . . . . . . . 42Constantly-open throttle valve . . . . . 28Conversion parts and modifications . . . . . . . . . . . . . . . . . . . 38Coolant

Mixing ratio. . . . . . . . . . . . . . . . . . . . 64Renewing . . . . . . . . . . . . . . . . . . . . . 94

Coolant level. . . . . . . . . . . . . . . . . . . . 90Cooling system

Cleaning . . . . . . . . . . . . . . . . . . . . . . 56Degreasing . . . . . . . . . . . . . . . . . . . . 57

Cylinder head coverRemoving and fitting . . . . . . . . . . . . . 74

DDiagnostic socket . . . . . . . . . . . . . . . 32Diagnostic testers . . . . . . . . . . . . . . . 32Diesel fuels

In extremely cold weather. . . . . . . . . 60Sulphur content . . . . . . . . . . . . . . . . 60

Dimensions. . . . . . . . . . . . . . . . . . . . 108Disposal of service products . . . . . . 64Drive control unit. . . . . . . . . . . . . . . . 31

EEmergency running program . . . . . . 29Engine

Checking for leaks and general condition . . . . . . . . . . . . . . . . . . . . . . 68Cleaning . . . . . . . . . . . . . . . . . . . . . . 55Oil change and filter replacement . . . 69Starting . . . . . . . . . . . . . . . . . . . . . . . 47Stopping . . . . . . . . . . . . . . . . . . . . . . 52

Engine brakeChecking the adjustment . . . . . . . . . 89Checking the condition. . . . . . . . . . . 88

Engine control unit . . . . . . . . . . . . . . 30Engine data . . . . . . . . . . . . . . . . . . . . 108Engine data card . . . . . . . . . . . . . . . . 24Engine oil

Extracting, draining . . . . . . . . . . . . . . 70Engine plate . . . . . . . . . . . . . . . . . . . . 22Environmental note . . . . . . . . . . . . . . . 7Exhaust brake . . . . . . . . . . . . . . . . . . . 28

FFlame-start system . . . . . . . . . . . . . . 26Flow improvers . . . . . . . . . . . . . . . . . . 61Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Fill ing the tank . . . . . . . . . . . . . . . . . 43Filter element . . . . . . . . . . . . . . . . . . 80Prefi lter. . . . . . . . . . . . . . . . . . . . . . . 77

Fuel additives . . . . . . . . . . . . . . . . . . . 60Fuel system

Bleeding . . . . . . . . . . . . . . . . . . . . . . 80

GGenuine Mercedes-Benz parts . . . . . 40Grid heater . . . . . . . . . . . . . . . . . . 27, 51

117

Index

9

HHigh-pressure cleaners . . . . . . . . . . . 56

IIndicator lamp . . . . . . . . . . . . . . . . . . 47Intake pipe

Checking for leaks . . . . . . . . . . . . . . 82

JJump-starting . . . . . . . . . . . . . . . 36, 106

KKerosene . . . . . . . . . . . . . . . . . . . . . . . 61

LLocation of sensors . . . . . . . . . . . . . . 20

MMaintenance instructions . . . . . . . . . 66Maintenance intervals . . . . . . . . . . . . 42Maintenance service . . . . . . . . . . . . . 67

OOil pressure . . . . . . . . . . . . . . . . . . . . 51Operating safety . . . . . . . . . . . . . . . . . 8Overview

OM 904 LA/OM 924 LA . . . . . . . . . . 12

PPersonnel . . . . . . . . . . . . . . . . . . . . . . 32Poly-V-belt

Checking the condit ion. . . . . . . . . . . 83Removing and installing . . . . . . . . . . 86Routing . . . . . . . . . . . . . . . . . . . . . . . 87Tensioning pulley . . . . . . . . . . . . . . . 86

Protection of the environment . . . . . . . . . . . . . . . 7, 32, 38Protective treatment . . . . . . . . . . . . . 58

SSafety and emergency running pro-gram . . . . . . . . . . . . . . . . . . . . . . . . . . 29Safety precautions . . . . . . . . . . . . . . . 36Service products . . . . . . . . . . . . . . . . 64Special lubricant additives . . . . . . . . 59Starter motor . . . . . . . . . . . . . . . . . . 111Starting the engine for the first time . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

TTelligent® engine system . . . . . . 32, 50Test values and adjustment values . . . . . . . . . . . . . . . . . . . . . . . . 112Tightening torques . . . . . . . . . . . . . . 113Transport and installation. . . . . . . . . 33Type designation . . . . . . . . . . . . . . . . 24

VValve clearance . . . . . . . . . . . . . . . . 112

Adjusting . . . . . . . . . . . . . . . . . . . . . . 73Adjustment . . . . . . . . . . . . . . . . . . . . 75Checking . . . . . . . . . . . . . . . . . . . . . . 76

WWarning lamp . . . . . . . . . . . . . . . . . . . 47Warranty entitlement . . . . . . . . . . . . 59Water . . . . . . . . . . . . . . . . . . . . . . . . . . 63Weights . . . . . . . . . . . . . . . . . . . . . . . 109Winter operation . . . . . . . . . . . . . . . . 53Work plans . . . . . . . . . . . . . . . . . . . . . 67

118

Contact

Mercedes-Benz will be happy to answer any queries you may have:

Mercedes-Benz Contact Telephone: 00800 1 777 7777International: +49 69 95 30 72 77

Internet

Further information about Mercedes-Benz and DaimlerChrysler can be found on the following websites:

www.mercedes-benz.comwww.daimlerchrysler.com

Editorial office

You are welcome to forward any queries or suggestions you may have regarding these Operating Instructions to the technical documentation team at the following address:

DaimlerChrysler AG, HPC: R822, 70546 Stuttgart, Germany

As at: 25.05.2003

Title illustration number N00.01-2194-31

Not to be reprinted, translated or otherwise reproduced, in whole or in part, without written permission.

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