Replacing sparkplugs on 2003 F150 4x4

ford
f150

#1

I just paid a princely sum to have a Coil On Plug (COP) assembly replaced and the Ford service guys recommended that I get my sparkplugs replaced (at a sum closer to a king’s ransom than a prince’s) so I decided to do it myself.



I have the shop manual for the truck but it does not give me the detail on the COPs. I need some advice on removing the COPs from the plugs. Do I just pull them off? At approximately $100 per COP, I want to be careful.


#2

On the two valve engines there’s a single bolt holding the coils. On the four valve engines the coils are pulled off the plugs. If there’s a cover above coils that’s a four valve engine.

Tester


#3

Use great care in removing the COPs. The rubber spark plug boot goes WAY down in the head, there is a spring and resistor inside, so don’t just yank them off…Sometimes you must disconnect an injector to get enough clearance… When re-installing the COPS, do not put much torque on that hold-down screw. You are threading into plastic…I spray a little silicone lube on them so they will not stick to the plugs the next time…

You can buy coil packs on e-Bay for a FRACTION of dealer prices. NEVER use a high-pressure washer to clean your engine. You will be buying more of those coils if you do…


#4

There were only two valve engines availible in the 97-03 trucks. The F-150 still hasn’t gotten a 4 valve modular engine yet, though the new DOHC 5.0L engine is expected to go into the F-150 in the near future.

The OP should be pretty careful in extracting and replacing the plugs, especially if he has the 5.4L. Even though the plug ejection problem was largely fixed by 2003, the heads are alluminum and the plugs themselves are rather unique in that they are longer than your average spark plug and some say that crossthreading is an easy mistake to make with depth the plug must go down in order to be properly seated.


#5

Do not try to pull them directly off. Try to wiggle them as you remove them.
Use anti-seize on the spark plug threads and diaelectric grease on the plug boots.
Do NOT overtighten the spark plugs. Many torque specs are a bit aggressive if you want to put it that way and this can lead to stripped or pulled threads.
This is especially true with tapered seat plugs. Snug them up, nothing more.


#6

Thanks for all the responses. I did not know about the aluminum heads, the depth of the boots, nor the fact that they are tapered plugs. Also, thanks about the pressure washing advice. Do we know each other? I was just thinking about getting my washer out and cleaning everything before I did the plugs. The EBay thought is a great help, too. If I mess one up, I will look there.
If I need it, I will be back for more advice.