Hi all, long time reader of the forums.

So I recently changed the plugs and wires on my 2003 c5. Pretty much all stock. Since then, I have been getting a random misfire. It isn't pulling up a code/check engine light which is a bit surprising because it's pretty obvious.

I have called a few shops around (Sarasota, Fl) to see if they could diagnose which cylinder it is but most don't have the right gear. I am still calling around, but been busy.

It doesn't start misfiring until it's warmed up. I removed and inspected all the plugs and reseated the wires (except #7) but those all seemed ok. Since it started doing after I did the initial plug and wire change I have to assume it's a bad plug, wire or I messed up something while changing them?

Anyone have any suggestions? I figure the fact that it doesn't start until it's warmed up might be an indication of the issue?

Thanks,
adaM

 

So, I took my car to the local GM/Chevy dealership to have the service department have a look. The said the #3 cylinder is misfiring. They said they swapped plugs, wires and ignition coil but the #3 kept misfiring.

They think it could be the lifter or cam bleeding down. They said the #3 cylinder does 170PSI.

Any thoughts from the forum? Since replacing the the plug, wire, coil is pretty cheap, I still plan on doing that (just in case). I would love to try replacing other stuff before I look into replacing lifters or a cam. =/