Ok so it's my buddy's 02 Z28 and it's throwing a code for Cylinder #7 Misfire. We have swapped plugs, wires, coil pack, etc and it is still happening. Now he has a light brown peanut-butter like sludge coming out of his PCV system. I am pretty sure that means he is getting a bunch of oil into his #7 cylinder, either through a crack in the intake manifold or blown rings etc. Either way we are tearing into it this weekend and I wanted any more .02 that you guys could offer.

Oh and I haven't personally seen the problem yet so all I'm going off is what he's told me. Obviously the first thing to check for is oil on the plug... so yeah just steer me in the right direction guys