BimmerFest BMW Forum banner
1 - 1 of 1 Posts

·
A sudden sense of liberty
Joined
·
3,939 Posts
There appear to be at least two distinct failures that people are experiencing. One is a failure of the main bearing; this appears to be an engineering (either design or assembly) flaw unrelated to over-revving the engine. The other is valvetrain damage related to over-revving the engine, similar to that seen in E36 M3s. This seems to be related to driver error.

However, as Nick points out, a number of cars with SMGs have experienced over-revs, and have also experienced engine failure. Also as Nick points out, it *should* be impossible to over-rev an SMG car. The engine computer has a fuel cutoff that theoretically prevents going much past the redline, and unlike manual tranny cars, the shift computer is not supposed to allow you to engage a gear that is too low for the speed you are traveling.

So, while driver error may explain some or all of the manual transmission over-revs, it does not explain the bearing problems or the apparent flaw in the SMG program. What is unclear is how common either of these latter two flaws are.
 
1 - 1 of 1 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top