2002 F150 5.4 SCREW 149K miles

Should the COPs be replaced on a regular maintenance schedule or just individually as they fail?

Over the past two years I have run into several instances of extreme hesitation, rough idle, etc. Replacing the COP boot (boot only) has fixed the problem each time except for one. The last incident I replaced both the COP and boot. There was a lot of moisture in the #3 well. I also went ahead and replaced all 8 boots on the last round. I recall alot of rust being in #4 well.

Rough idle and pretty bad hesitation on acceleration is back. Been running fine for about 6 months. Ran just fine this morning. Stopped to get gas. Filled her up. Started the truck, put in drive and rough idle and hesitation/mis-fires all the way home. It was like wow...where did that come from. After awhile it put up P0304 and P0316 codes.

Anyway, I am wondering if COPs are good until they actually fail or do they degrade overtime and should be replace on a regular basis?

Thanks.
Jim

 

I think maybe the rubber boots connecting them to the plugs might be worth swaping for new ones once in a while

we used to replace spark plug wires every so often right ?

K this is why I think this

years ago my 79 f150 that I bought off a friend never started in the rain or fog
one day , I rinsed off the truck and it would not start

I had just backed it outta the garage
when I pulled a boot off the distributor water poured out of the boot

this water had been sucked right through the rubber boot out of thin air
(I never hosed anything under the hood)

now , if water sitting in the plug wells on a mod motor kills coils then the same issue as my 79 had may apply with the old rubber boots between the coils and plugs that never get changed until the coil pops - the boots may have water in them that's been absorbed from the air & when enough collects to kill the coil it dies

 

I replace the boots and springs whenever I replace plugs. I replace COPs ONLY when they actually fail.

Yes, this is correct.

 

If you have cash you can if you want. They dont need to be replaced until they dont work. I would replace boots for sure but the coils work until they dont..

 

Thanks for the input. Think what I'll do is buy one cop/boot from Ford and just keep it on hand.

Btw, replaced #4 COP/boot (Motorcraft) and truck is running fine again. The boot that was already on there was only about 6 months old but went ahead and replaced it with the boot that came with the Motorcraft COP.