Originally Posted by Goofyguy
There are a few noises that start with a BMW, first you have the DTML pump which does a quick pressure test on the fuel tank to see if there are any leaks. Then you fire up the car and if its a 330 or 335 you will hear the exhaust valve closing (metal rattly sound). Then if its a coupe the seat belt hand ups, a few tones, then the radio. Its a poorly designed orchastra of annoying. Mine has a rattle at high speeds on the highway coming from the back seat area.
I think I hear that pump every time you open a door, unlock your doors, correct? Small humming sound.
I'm not so sure I've ever heard the exhaust flap closing. I'll have to pay attention to that.
Regardless, good info, thanks!