yes this was the first of many problems I had after buying a used e70 3.0 xdrive. The i6 comes standard with rear air suspension while the 4.8 v8 has both front and rear. An error would pop up saying "level control system malfuntion". Id have to dig for the invoice but it was repaired at BMW long beach dealership and ran a little under 2 grand including labor, parts were expensive as usual. Dealer said after the diagnostic(which they charged for) that the air bags were no longer holding air and needed replacing. Made sense since the only time the rear would be lower than the front was after it sat for about an hour, driving would sometimes level it out but eventually it couldn't even do that. If you end up taking it to the dealer, try to make sure they reset the computer as to this day the level control system malfunction still pops up randomly thanks to early idrive and its endless list of anomalies. The suspension holds air perfectly fine though and havent had an issue other than the annoying non accurate error that pops up occasionally(normally after filling the tank, a load in the trunk, or even having passengers ive noticed can trip it) Oh and the noise is the air compressor, it sometimes dosent go off and eventually the error will pop up to make it shut up but this only happens after a cold start, isnt consistent and the ride remains unaffected. Thats bmws for ya
