Spark Plugs May be Difficult to Remove on Lincoln Mark LT

Our technicians tell us the spark plugs in the 5.4L V8 engine can be very difficult to remove. Ford has issued a service bulletin (08-7-6) to address this issue, which includes a recommended procedure on how to remove the plugs. Failure to follow the recommended procedure can result in the one or more spark plugs breaking off in the cylinder head.

The recommend procedure is as follows. Using this procedure will greatly reduce the chance of breaking a spark plug.

1. Break the spark plugs loose when the engine is warm.
2. Turn each plug 1/8 to 1/4 turn and soak the treads with 1/2 to 3/4 teaspoon of Motorcraft Carburetor Tune-Up Cleaner or a quality penetrating oil. Do not try to remove the plugs at this time.
3. Let the threads soak for at least 15 minutes.
4. After the soak period, tighten and loosen each spark plug, working it back and forth until the turning effort is reduced. Then, you can remove the spark plug.

There are special tools available to remove the broken spark plugs and repair shops will often charge additional labor time, over and above the quoted spark plug replacement cost, for the removal of each broken spark plug.

RepairPal Verified
Average mileage: 71,150 (39,000–99,450)
Engine affected: 6 Cylinder
3 model years affected: 2006, 2007, 2008
6 people reported this problem
3 people shared problem details
2007 Lincoln Mark LT- 6 Cylinder39,000
The truck had to get towed into the shop because it lost power, then died. My mechanic indicated that it was probably the coil ( which would be under warranty). The dealer then towed the car to the dealership. They determined that it wasn't the coil, but the plugs. Because of the poor design of the plugs, 7 out of 8 broke. What should have been less than $20 to replace them turned into almost $800! Almost all of that was for labor. When I contacted Lincoln, they basically told me...oh well. The mechanic told me that they knew it was a problem, but weren't doing a recall.
2006 Lincoln Mark LT- 6 Cylinder99,450
I brought my 2006 Lincoln mark LT, to the ford shop and they had 4 out of 8 plugs break off in the head. It cost $460 to replace spark plugs????? I remember, "back in the day", when I would do it and it cost me about $10. But they didn't last 100,000 miles. I now have 197,000 mile and get to do this again... Oh Boy!
2006 Lincoln Mark LT- 6 Cylinder75,000
Ford's TSP was followed to the very letter, but still 7 of 8 plugs broke.
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