Best bet is to do a compression and cylinder leakdown test. Normally, you don't worry about bmw engines that seem to be running well, but I have concerns with these cars. Many have had VERY hard lives, and if one of them is driven hard with an unbaffled pan, and/or low oil level, engine life can be drastically shortened. Worse, M3 engines are VERY expensive. Better safe than sorry S. Chamberlain BMW CCA Ombudsman