I have a 2001 F150 SCREW with 135,000 miles. Today I just replaced my third coil. So far I have replaced the coils on cylinders 5 (sometime in 2003), 6 (this June), and 7 (today). The service manager of the local dealership says I should expect these kinds of failures given the mileage, but also says that I may or may not have to replace any more in the lifetime of the truck, it "just depends". I asked if replacing the boots or taking extra precautions to keep moisture away from the engine was warranted, he said "No, it's more a problem with buildup with heat in the engine compartment". Sounds like BS to me, seems like Ford should have been able to design for the expected heat environment.
I note from searching this forum a fair number of posts regarding replacement of COP's, but I can't tell from these posts if anyone thinks this is a result of poor design and/or faulty components, or if everyone accepts the frequency of coils needing replacement as just one of those things that comes with the territory. I'd like to know what the community thinks...
Also, has anyone else complained to Ford and gotten any kind of redress??
Many report that not using original Motorcraft plugs makes their motors miss. Sometimes only on one cylinder at a time - so it looks like a COP problem. So, replace the COP, and the miss goes away. However, the real problem was the plug.
Well at that kind of mileage all boots should be replaced and make sure dielectric grease is used on new ones.If you look at one of the coils that you replaced what was the ohms measurement of it.I bet you would see a open or a very low resistance.
Inside the coil is a capacitor that goes bad.(high heat)this cause the misfire.
You should be thankful you haven't had a plug blow out.
Because when they blow out the wreck the threads in the head plus destroy the cop.
Chk all your boots