Ford Spark Plug Problems

What Problems Exist?

• 2 valve engines may have spark plug threads strip. This can also cause the spark plug to blow out of the engine while it is running.

• 3 valve engines have a unique spark plug design. The spark plugs can become seized in the head and break into two pieces.

What 2 valve engines are affected?

• 2 valve engines include the following• 4.6L V8, 5.4L V8, 6.8L V10

• The following 2 valve engines are affected• 1997-2004 Ford Mustang• 1997-2008 Ford Crown Victoria• 1997-2004 Ford Expedition• 1997-2008 Ford E-Series• 1998-2004 F53 Motorhome Chassis• 1998-2004 Ford F-Series• 2001-2005 Ford Excursion• 2002-2006 Ford Explorer and Mercury Mountanier• 1997-2007 Lincoln Town Car• 1997-2008 Mercury Grand Marquis

What 3 valve engines are affected?

• 3 valve engines include the following• 4.6L V8, 5.4L V8 VIN 5, and 6.8L V10

• The following 3 valve engines are affected• 2005-2008 Ford Mustang• 2004-2008 Ford F-150• 2005-2008 Ford Expedition, F-Super Duty• 2006-2008 Ford Explorer• F-53 Motorhome Chassis• 2007-2008 Ford Explorer Sport Trac• 2005-2008 Lincoln Navigator• 2006-2008 Lincoln Mark LT• 2006-2008 Mercury Mountaineer

2 Valve Spark Plugs

Torque

• Threads may strip during spark plug removal or installation.

• Plugs may also blow out during normal operation.

• Spark plug torque is critical!• Spec is only 7-15 ft.-lbs.

• Make sure to look up the exact spec for your application and use a proper torque wrench.

• If the spark plugs are not properly torqued, they WILL cause problems in the future.

• There are only 4 threads in the aluminum cylinder head, the following slide is a picture of a head off of the vehicle.

What happens when the threads are stripped?

• If the plug blew out, a new coil on plug assembly will be necessary. Ford sells a repair kit, and there are many other available in the aftermarket to attempt cylinder head repair in vehicle. • Advise the customer that the repair will not work 100% of the time and the

head may need to be further repaired in the future.• Follow the instructions of your tool closely, don’t skip any steps.

• The spark plug may bounce around, and cause damage to fuel injectors, engine harnesses, the hood, etc., be sure to perform a thorough inspection of the damage.

• The following slides will illustrate what a broken ignition coil looks like, and the plug that broke it.

What happens when the in-vehicle repair doesn’t work?• Sometimes the thread insert does not hold. It may last a year, month,

day or minutes. When this happens the head will have to come off and be repaired from the inside.

• It is easiest to remove the motor to service the cylinder heads in most vehicles.

• The following slides show an actual case study of a failed repair.

13

03 Ford F-250 5.4 2V

Runs Rough

14

Using Scan Tools

• OE and aftermarket scan tools have powerful tests built into them

• The Ford IDS is a great example of this

• The power balance test shows us what cylinder is misfiring

• The relative compression test checks the mechanical integrity of the engine

15

16

Analysis

• The power balance quickly identifies that we have a misfire on cylinder 2

• Next we will test compression using the tool

17

18

Diagnosis

• Quickly and efficiently we find out that this vehicle has a mechanical issue.

• By the time the technician actually opened the hood of this vehicle he knew he has a mechanical misfire on cylinder 2.

• After compression and leak down testing he finds a tuliped intake valve.

Diagnosis Continued

• The intake valve became tuliped because the vehicle ran lean.

• The engine ran lean because the thread insert used to repair a blown out plug became loose, causing the plug to not fire.

• The engine ran very lean causing the valve to get hot and tulip.

• The following slides show the spark plug and insert removed from the engine. Notice how melted the electrode of the plug is.

The Fix?

• The engine had to be removed, and disassembled so the head could be sent to the machine shop.

• The machine shop installed a new valve. The also installed a thread insert from the inside.

3 Valve Spark Plugs

Removal

• Plugs may break into two pieces during removal.

• The plug is uniquely designed because a regular spark plug could not fit into the limited head space because of such large valves.

• Ford TSB #08-7-6 addresses spark plug removal. *Note* this is Ford’s procedure using their tools. Aftermarket procedures may vary and tools will vary.

• The spark plug hex is 9/16”, so a special socket must be used.

Removal Continued

• Some technicians in the field report that doing a top-engine cleaning prior to spark plug removal helps. This is because carbon buildup at the tip of the plug is what causes them to break, not corrosion.

• Some technicians try to break the plugs loose a little bit and soak carb cleaner or penetrating oil down the spark plug tube.

• Some technicians are using cordless impact wrenches to remove the spark plugs with success.

Matt’s Removal Method

• I do not try and break the plugs loose and use penetrating oil. The many times I have tried this I found that the plug would break within the first 1/8 turn anyways.

• I do not use any top engine cleaners, but I’m not against it.

• I use a 3/8” OTC spark plug socket. P/N 6900

• I use a cordless impact gun. The cordless works much better than a pneumatic wrench, because there are less intense impacts and more of them.

• If the plug breaks using this method, in my opinion there was nothing you could do to prevent it from breaking.

What happens when the spark plug breaks off?

• You will end up with a piece of spark plug that looks like this.

• The rest of the spark plug will have to be extracted using a special tool.

Lisle Special Tool P/N 65600

Extraction

• The Lisle extractor is the preferred tool to the aftermarket.

• This tool will push the porcelain of the spark plug tip in and allow an extractor screw to remove the rest of the spark plug.

Problems and Solutions

• If trouble occurs during spark plug removal, make sure the porcelain pusher tool was fully installed and fully engaged.

• The extractor screw is only good for about 4-8 extractions. After that it becomes too worn out. The extractor screw is available separately from most tool dealers.

• If all else fails, engine removal is sometimes necessary. Make sure your customer understands this before repairs begin.

How does the customer get billed?

• Ford recommends actual time.

• Average book time to replace spark plugs is 2-4 hours, depending on vehicle and engine. This is if none of them break.

• Average extraction can take 15-60 minutes if all goes well.

• Good rule of thumb, bill your 2-4 hours. Then bill .5 to 1 hour extra for each broken plug. If the engine has to be removed, more time will be needed.

• Also be sure to bill $10 - $20 tool fee for each extraction. This is because the tool will wear out and have to be replaced. This should be a shop supplied tool, not technician supplied!

• After a technician becomes proficient at removal, money can be made!

Installation

• Torque is critical! When you look up the spec, you will find that the torque spec can be double some 2 valve motors.

• Apply anti-seize to the ground electrode. Nickel anti-seize is a must. It may cost a lot of money, but can be billed to the customer. • Permatex and Locktite P/N 77124

• Ford Motorcraft P/N XL-2

• Use only Motorcraft Plugs• There are known problems with Autolite plugs falling apart.

• Champion has a one piece “problem solving” plug. This plug is only available in 1 heat range and has been known to cause misfires.

Spark Plug Intervals

• Ford originally recommended that the spark plugs be changed every 100,000 miles. This is far too long for this style of plug.

• Most dealers are now recommending 30,000 mile service intervals.

• If you remove an ignition COP and see paint on top of the spark plug, the plugs are OE.

So how common are all of these problems?