I’m having a weird misfire problem with one of my cylinders, I’ve replaced the coil packs and spark plugsand cleaned the maf sensor multiple times . It will be running and driving fine but once it starts to get warm or goes above 70 the cylinder starts misfiring. If anyone has some guesses to what it could be it would be appreciated. It has 140,000 miles.

 

just did a compression test everything was fine, also checked the cylinder heads and all but 1 are super black and oily.

 

make sure you have the coil pack plugs correct, there are 2 that are easily swapped by mistake

 

Will do, is it possible for too much oil Ina cylinder to cause it too bog from a bad valve seal?