Originally Posted by mrad01
BMW replaced the crank and bearings in my 07 e90 M3, and the knocking noise remained. In the end, Germany sent down a brand new 2011 engine which I'm just about finished running in. The noise is gone now.
That is some damn good service. To have an engine running to spec, except for a noise, and have them replace it? Yes, that is the right thing to do so as to avoid a possible catastrophic failure, but many manufacturers would not have done that.