Disclaimer -- I've never owned a Ford with COPs. This is just some stuff that I ran across. COPs are discussed often enough so that I thought I'd pass it on.

This site claims to have some replacement boots that can extend the life of a COP.

MAGNECOR Race Wires - Ford 4.6/5.4 coil boots


This site talks about testing misfires and makes the point that many returned coils are actually good. Unfortunately, they use seem to use some specialized equipment for the tricky parts, but it's a little food for thought.

Coil-over plug misfire - Automotive Service Professional


read or ignore as you see fit,

hj

 

very rarely do i replace a coil. 9 times out of 10 a new boot fixes the missfire.

 

nice lesson hj, thanks.

 

Boots have repeatedly been the issue with many of the misfire problems encountered in the V10 & V8 forums.

I did swap out the OEM COP's for Granatelli's and within the first year one by one they began to fail, the boots not the problem at all. Oddly enough when one would fail it was replaced with a new boot and a removed/saved OEM COP, never another misfire or CEL at all.

I'm sold to first check the boots and plug but when necessary use nothing but Motorcraft or whatever brand Ford sells as their own---270+ K miles still going strong!

Thanks for the links---great reading!