What do you mean cracking? Are you using Motorcraft coils?

 

No, not motorcraft, yet, so far duralast and masterpro, thy are cracking just above the boot on the plastic housing. Was told last night that once you replace 1 you have to do them all, so if that the case that kinda sucks.

 

Why is that? I've only replaced two coils on my '02 5.4

 

Ours didn't. One of the coils went dead completely and it ran on 7 cylinders for a week and about 300 miles (happened during a trip). No codes or check engine light.

 

Yeah, hooked it up to one of Oriellys readers and its saying coil in 10th cylinder, just replaced it again and the engine light went off for a few, then it started missing again, pulled the coil and no crack. So now Im wondering if its just a bad plug and thats somehow nuking the coil. No clue why you would have to change all of them, just what a buddy of mine told me.

 

No need to change all the coils out. Nothing will be gained except an empty pocket book. You should however replace all the boots when doing a plug change or if you suspect age is starting to be an issue.
As far as replacement coils most guys are going to recommend Motorcraft replacement.

 

ConstableOnPatrol

 

Just bought new plugs and boots tonight, see how it goes after I put them in tomorrow.

 

Well, after new plugs, boots still nothing, thinking the problem might be in the wiring harness that plugs into the cop's.

 

IDK on that v10 but I know on the 4.6L and the 5.4L I find the last 2 cylinders the plug is cracked or lose often. I guess since it's hard to get in there people try releasing it with needle nose pliers or something and break the clip. That's what happened on the last two expeditions I've worked on. The previous mechanic broke the clip causing them to misfire once the plug losens.

 

I agree...Absolutely not, you only have to replace a bad coil, not all of them. Probably 90% of the reported bad coil problems are not actually the coil but a bad boot. These coils got a bad rap for going bad due to the boots going bad with age but they are pretty reliable.

 

Whoever told you to change ALL of the cops...tell this person to
take a hike please.
You change one as needed.
The most likely problem you are having, is that you are buying
cheap auto parts store cops.
If you go find you a good deal on some Motorcraft cops at Ford,
You would have much better luck.
I really dont think that its in the wiring.
I also dont think that its the plug.

Just by chance, is the boot kinda burned looking on that cop???
Do you hear any ticking sounds in that general area of the cop???
If it is, then you have a plug that is loose, hot combustion gases
are blowing on the cop overheating it.
Eventually the plug will blow out completely, sound like a gun shot
and destroy the cop and plug too.
This is usually what happens on the Ford modular engines.

 

No, the boot dosent look any diferent than when I put them in, I havent eard any noises from that area at all, the only noise I hear is after I shut the engine off is normal cooling down noises. Now Im noticing that at initial start up the engine bogs down and sputters for a bit but after about 5 minutes runs normal.


Thanks

 

Wow!..........you never stop learning.

 

I agree, never change all the cops. I wish I had all the good cops everybody threw out, I would be rich.Also; keep your ears open for ticking noises and act fast (plugs). Don't discount it as an exhaust leak.