I have a 2006 318i that I love and adore but has given me a lot of problems lately.
Currently if I press the throttle even a tiny bit there's a faint rattling, regardless of whether I am in gear or clutch down or up. It happens also when driving usually at low speed.
I recently had to change the bearings in my rear diff to sort out a whiney noise. Not sure if that is related.
Any ideas? Cheers.