Strange Engine Sound below 2000RPM
I just had a 2006 Cooper S go in for a replacement clutch and flywheel, and on return it sounds very rough below 2000rpm, akin to a spluttering tractor.
From the driver seat, it sounds as though you've changed into far too low a gear, even in first from take off. As the revs hit 2000, the engine suddenly becomes smooth. The same with 2nd. The only other way I could describe it would be to say below 2000rpm it sounds like a diesel, or as if something is rattling or lose.
Has anyone got any suggestions?
The mechanic thinks there is nothing wrong, and a trip to BMW came back with the same answer.