|
I had the exact same problem on my 740. Turned out that the exhaust and muffler system was incorrectly mounted and it's edge was too close to a crossmember, cannot remember exactly where. In any event it seems that the sudden and uneven cooling by the road water caused contraction of the exhaust pipe bringing the muffler into contact. This only ever happened with car fully warmed up, at faster speeds (over 40) and in very heavy rain or going through big puddles.
Inspect your exhaust system, look for some component that is very close to frame parts. Problem will not be the engine or tranny.
--
David Hunter
|