Not even 3months/3000km after the change, the sound is back. Didn't have time to bring the car back in yet, but WTF?!
I checked several E90s and i found none with this problem. Replacing the vibration damper resolved the problem temporarily, but i'm afraid that is not what's causing it.
The sound is present likely when it's damp/wet/cold outside, and not so likely when it's hot. Could the steering pump be faulty, thus putting a bigger strain on the belt, causing slippage?
BMW 320 dA LCI, BMW PPK - 197HP, 2010, sapphire black, steptronic
Last edited by EQUANT; 11-01-2011 at 10:37 AM.