View Full Version : Bad coil pack on 5.4liter F150's? and do they all need to be replaced?
01-02-2009, 12:11 PM
so my 2000 F150 v8 5.4 triton is a great truck as I think anyone with one with one will agree. The only recurring problem seems to be the coil packs will go bad all of sudden, causing misfiring and a very bumpy ride. When this first happened a few years ago, I replaced them all and the truck was good for 3 years. The 1 and 3 coil went bad last winter, I took it to STS and just had those two replaced, and the truck was still running rough, so I took it to a buddy and he said they replaced the coils but not the plugs that go with those coils, so he just replaced the two spark plugs on those coils and it was fine (very inexpensive fix and it was one of those where you are like, wow thats all it was!). All of a sudden this week the truck is running rough again- so i take it to my new mechanic (who i think i can trust) and he replaces the #5 coil, says another one is going but he cant isolate it yet, and they all should be replaced at once. 8 coils @ $120 plus $75 in labor for each one and we are looking at alot of money I dont want to spend. I drive the truck off the lot and it runs great. Two days later the check engine light is back on and its running rougher than ever! Should I have him just replace the bad coil or all of them? And should the spark plugs be replaced also? Im so confused over these darn coils!
01-02-2009, 06:17 PM
wow, that sucks. I have a little experience with those coil packs. I think there is something else going on if you are going thruogh that many coil packs. I think the trucks electrical system should be checked before investing any more money. How many miles on this truck on question. I have heard that the coils usually last about 150000 miles and than they should be replaced only as needed. My buddy had one fail at 140000 and than another one at 145000. After the second one, he decided to do all of the remaining seven.
01-02-2009, 07:59 PM
i have replaced 5 on my 2000 f-250 with 105k miles.
01-02-2009, 08:16 PM
replaced all of them in 2004 (the truck had about 40,000 miles on it) then the #1 and 3 in 2007 when the truck had about 100k and now the truck has 125,00 miles. Actually the truck DOES have an electrical problem- a few years ago every time it rained all my electrical went crazy, turns out there was a leak in the windshield that was dripping water into the fuse box. Sealed the leak and havent had problems since, but Im guessing it did some sort of damage.
01-04-2009, 11:39 PM
When you get a check engine light, what code does it show. IIRC a bad coil pack will show as a misfire, the code being 010x, with the x being the cylinder number. If you have this code, try switching the coil packs between the misfiring cylinder and another cylinder. If the misfire switches cylinders, you have your culprit. If not, then it could be an injector or wiring problem. Reading and interpreting the check engine codes is critical. If you don't know the code, you are literally taking a wild azz guess as to what the problem is.
01-05-2009, 07:25 PM
i have replaced 5 coilpacks and never had a check engine light come on. changing a coil pack is easy and not terribly expensive ($90) if you can figure out which one to replace when it starts missing......
R & R Yard Designs
01-06-2009, 12:22 AM
If you have this happen, when you do replace it you have to seal around the plug and the rubber boot with dielectric grease, but a dab on the top of the plug, and on the bottom and top of the rubber boot. What happens is that it gets water down there and it shorts through the boot and blows out the pack over time.
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