Originally Posted by Steve30
The original rod bearings and bolts in the 01-early 03 cars were not to spec or BMW quality standards and wore prematurely (or caused engine destruction). This issue is on ALL S54's though. I've seen 03.5-06 rod bearings that were completely down to the copper... I've read every thread/article on the net about rod bearings and even 03.5-06 cars are having this issue. The problem seems to be a mix of everything from long oil change intervals to consistently revving the engine to or over 8k. Apparently the engine was designed to safely rev to 7600 but BMW marketing just bumped it up to 8000. Most of the wear seems to occur on the top bearings which is a result of high rpms. The piston is being forced down with extreme pressure and the top bearings makes contact with the crank journal.
So can you get modified parts to make it safe to 8000 or are you going to keep it at under 7600?