JeepinLife
Caught the Bug
man oil on the plug isn't good. Run the compression check. As for the exhaust if its blue thats also oil, if white it means you have water leaking.. either could be from a cracked head. Or bad rings.
I had been experiencing a mild misfire for a few days which got worse yesterday, and then I got the P0302 code after revving the engine just like you. I swapped out the coil pack and I noticed improvement, but it was still off. Next, I replaced all of the plugs and wires and it went away completely. I drove several miles over country back roads, the interstate, and several minutes idling in a drive-through after leaving a NYE party and it never returned.
I noticed that all of plugs were slightly out of gap and that there was chaffing between the wires for cylinder 4 and 6, but none of the plugs were damaged.
As best I can tell from my frantic research of various forums yesterday, the P0302 code means a misfire on cylinder 2, and the best solution to cure the problem on the 3.8 is a complete tune-up, while on the 3.6 the solution is a new head. That of course varies from Jeep to Jeep, but that's the pattern that I learned.
Damn LoPo...sucks to try and chase down motor gremlins. I'm a dumbass when it comes to motor issues and end up having to rely on a shop. Hopefully you can get this worked out soon.
Hrm ok, that's good to know. I will look at sourcing the correct wire kit and perform a full plug replacement. Any advice on how to get to the plugs on the passenger side? It looks super tight in there and I have large hands. :blush:
Congrats!!! I'm glad that it worked out for you, and I also felt a great deal of relief when my misfire disappeared and the idle was smooth. For me, that two hours of cursing and cuts was worth it to have my Jeep driving like new again and eliminate the check engine light.
BTW, you may want to consider changing your ignition coil pack too. It's relatively inexpensive compared to other late model vehicles, easy to access, and easy to replace. Better to replace it on your terms, rather than having it go out on you later at an inconvenient moment.
i had the same symptoms on my 07 wrangler and after replacing spark plugs, wiring, and the ignition coil the problem is gone