Originally Posted by persian54
so what happened to cause this..?
I'm not sure yet. Will require tearing the engine apart to determine the official cause. I'm in the process of determining whether it is worth it to tear apart / rebuild the current motor or buy a replacement. Obviously it will not be worth the time / money to determine the cause if I plan to scrap the existing engine.
To be clear - this is not an M3 engine problem. I witnessed M3's running flawlessly at the track all day!