I have been working on a 740IL for to long now trying to find this rattle noise. It only happens when you first accelerate from a stop. It changes pitch and comes and goes when you turn the steering wheel either way. It happens when its cold or hot. The noise sounds like its coming from the drivers side lower dash/kick panel area. I can only describe the noise as a worn out speedo cable, but I know these cars have electronic speedos. I have 16 years in the automotive business and I have never been beat by a noise, but this one has me stumped. And by the way, the car is sold and I need to fix this problem ASAP. Any help would be much appreciated.

Hmmmm. I know the heating system has some "stepper motors" which change how the air circulates. On my car is sounds like a "click, click, click", but one that malfunctions might sound like what you describe. If you have the heater control in "Auto", try one of the fixed settings, say direct the air to your feet only and see if that changes anything.

If it does, go to www.roadfly.org and search the E32 forum for posts by "Sean & Johan", who have their own website with lots of info about the heating system, know as IHKA.

Sort of a wild guess, but you never know...

The climate control has no affect on the noise. It doesn't change if it is on or off. :banghead: