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I have a 2016 C7 Z06 with 26k miles on it with an intake and exhaust. When I first start the car when it is cold after 5 seconds stabitrak, service rear axle, and engine light starts flashing. I receive a pending P0304 misfire on cylinder 4. I read all the forums and first I tried to charge the battery and start the car, I then replaced the battery and removed, lubed, and reinstalled cylinder 4 spark wire. Once I cleared the code the car continues to drive fine and strong, until I do a cold start again I get the codes. I then replaced cylinder 4 spark wire with a new plug. Continuing, I then pulled the plug and found oil. See pictures below. I also pulled cylinder 1 to compare, which did not have any oil on the threads. I replaced the plug and the car was fine for 4 cold starts. 5th start everything came back. I have not pulled the plug yet, but I am assuming it probably has oil all over it. Checking on here to see if anyone has any suggestions or guesses?
I still have my extended warranty, but I worry bringing the car to the dealer with an intake and exhaust as they would love to blame everything on that and void the warranty. Would I have better luck with MTI Racing in Atlanta that specializes on Corvettes, but they are very pricy.
Before changing the coil i would check the wire on the other end under the coil cover i was having problems with mine and the ign wire was not fully seated on the coil
Before changing the coil i would check the wire on the other end under the coil cover i was having problems with mine and the ign wire was not fully seated on the coil
Did you figure this issue out? I literally have the exact same issue, same year and model.
Did you figure this issue out? I literally have the exact same issue, same year and model.
I've had the same thing happen twice on my 16 Z06, both times it was the alternator.. It was over-charging..
I've also had a coil to go out. It just skipped.. Good point about those.
I've had the same thing happen twice on my 16 Z06, both times it was the alternator.. It was over-charging..
I've also had a coil to go out. It just skipped.. Good point about those.
How would over charging cause a misfire and oil on plug? That seems odd
09-19-2023, 01:23 AM
Help - P304 Misfire Oil on Plug
