So I was heading home a few days ago and my CEL started blinking at me. I checked the code and got a P304 - cylinder 4 misfire. I nursed it home and tore into it thinking the coil was bad since the plugs had been replaced in the last 10-15k. So pulled the plug and it had tons of corrosion and #2 was even worse. 2 of the 6 were properly tightened by the dealer and coil 5 was loose. Every cylinder bank but 1 had oil on the plug and all were badly corroded. I have spilled a little oil when topping up but could it go into the cylinder and burn up my plugs? I just want to be sure my piston rings are not the culprit.

Thanks,
ceepyou

 

Was the oil outside or inside of the engine (ie. The side the coil connects to, or the side that ignites the fuel/air)? Outside could be a valve cover gasket, inside, much larger issues.

 

The oil was on both sides of the plugs. In talking with IPD, they mentioned that it could be the oil cap gasket leaking. I was unaware that those should be changed w/ each oil change. BTW, I chaneged the plugs with Bosch platinum 2's, cleared the code and it came right back. So I'm heading over to IPD to pick one coil pack up and those gaskets as well.

 

Okay, so it was a coil pack. I replaced one and then another went that day (cylinder 2). Got two more just in case. Replaced that and now everything seems fine. I have a spare in case another goes. Also, IPD said that if the oil cap seal doesn't fix the issue, then it is probably my PCV system.

Thanks Again,
ceepyou