i am considering an f150, but i have heard there were problems with spark plugs coming loose, and damaged threads. are there certain years or engines to stay away from?

 

The 5.4L and 4.6L 3 valve engines are bad about plugs breaking off in the heads. We have run into plugs blowing out on Crown Vics and F150's both. There is no rhyme or reason to the problem. From 2005 to 2008 have the funky plugs. They changed plug design in 2009 again.

 

I looked under the hood of my 05 4.6L; looking for the plugs because I used to change them out of my other Ford. I couldn't find them anywhere above the valve covers. Are the plugs located at the top of the engine just at the intake manifold or below the valve covers near the exhaust manifold. I also tried to look up some files online to see how they are seated in the block or whatever. YOUTUBE.COM had a good picture of the engine in operation but I couldn't trace any remnants of plug wires or boots, or anything that would resemble spark plugs. What did Ford do?

 

The spark plugs are located under the coils. The coils are located under the fuel rail and held in place with a 7mm headed bolt. There is one coil for each plug. Yes they are at the edge of the intake just by the valve cover gasket.

 

I have a 07 Harley f150 i just had the clutch fan replaced on. The air would quit when truck sat in 90degree sun. Compresser clutch would not engage. Twice while i had the hood open and windows done airing out cab i heard clutch fan speed up and compresser clutch engage to make air work. Once was at Ford dealer where mechanic said clutch fan bad. He stated if it slowed down air would not work. Ford replaced clutch fan and 4 days later on a hot afternoon it happened again. Anyone have any ideas.

 

I have an 01 5.4 and had a problem with one plug being "spit" out of the head. Had to have a heli-coil put in it. Make sure that you do not change the plugs with even a slightly warm engine. Another trick that I have heard with the V-10's is to pull al lof the coils, and spray a penetrqant, like PB Blaster as close to the base of the plugs as you can, then let them soak for a couple of hours before breakking them free. I have been told that there are only 3 threads holding the plug in.