1992 525i:

So i took my engine cover off and pulled my coil packs for grins and to my dismay I found cylinder 2 and 5 having oil in the plug holes. Cylinder 6 has a yellow/brown residue as if oil had been dripping from the Valve Cover and down into the plug holes. There was no sitting oil in #6 but there was in #2 and #5, #2 being the worst. I am hoping that (since my coils are still ok) there is no escalated problem and replacing the valve cover will remedy this?

Secondly, every now and then, I will very quickly blip the throttle from idle (to hear the motor sound) or when rev matching and sometimes I will get a "POP" from just infront of the fire wall. It sounds like a backfird, only its coming from up front. Could this be the sudden burn of the oil thats in the spark plug holes? If not, what the heck is this sudden firing sound, it almost sounds like a miss but all my coils and (to my knowledge) plugs are good. Coils were replaced but 15,000 miles ago (with Bosch). I didn't want to remove my plugs, knowing that oil would fall down into the combustion chamber and I am not sure how ideal that would be. Can anyone give me information on what i need to replace, and part numbers for the gaskets/o-rings? I can't find them in my ETK. I have a 1992 525i 5 Speed (build is 9/91).