'97 740il - Noises from HVAC system

[nsohn]

There's a thumping/pulsing type of background noise that seems to come from the HVAC system - noise goes away when climate control is turned off.

Does anyone have any clues or experience as to what may be causing this?

Thank you.

Ned

[iexcell2]

Have you found the source of this noise yet? Mine makes a similar noise, it kind of sounds like there is water in the dash.