m5board.comoholic (>1000 posts)
Join Date: Feb 2007
Location: Atlanta, GA
Thanked 316 Times in 215 Posts
I had a similar problem, and it turned out that the heat shield was rubbing against the exhaust.
2006 M5--Sapphire black/sepang
Dinan: free flow exhaust, Stage 3 engine software, high flow throttle bodies, high flow air mass meter/intake Assemblies, stage 2 suspension, 13% underdrive crankshaft pulley, 5.8 liter stroker engine, Dinan middle exhaust section, custom headers (I think I am finally done)
2011 Space Gray ZCP E92 M3; two-toned black and red interior; Dinan 4.6 liter stroker engine, intake, exhaust, midsection, pulley, and throttle bodies.