I've been having a bad shudder for a couple weeks, finally narrowed it down to a misfire on cylinder 1. I have a new coil for it and plan on replacing it tomorrow. Do I need to replace the plug also? It has about 50,000 on it as I already had them replaced at the dealer. Just wondering if I would be good to just swap out the coil or if the plug needs to be replaced also.

 

If this is a 5.4 3 valve with 50k on the plugs, it wouldn't hurt to replace them all. Ford is now recommending 60k plug changes with this engine.

 

glc, Is that just for the plugs or the plugs and coils? I have just over 60,000 and I'm starting to notice a misfire.

 

It is a 5.4 3v. When did Ford switch to 60k? I really don't want to replace them all again, I remember that $600 bill too well from the first time.

 

Just the plugs. The coils generally last a lot longer than that, but you should replace the boots and springs when changing the plugs.

They switched to 60k when they found out that the 2 piece plugs were sticking and breaking when being removed due to carbon deposits on the ground sleeves. *IF* the shop that changed them did it properly and used high temperature antiseize on them, they should come out a lot easier this time and the bill should be about half that.