I have an 04 Allroad with 37,000 miles (still under warranty, and is a CPO (certified) car so the warranty is out to 100,000 miles. I notices this AM that the front suspension was down Low rider style. I had it set on the lowest setting the past 2 days as I was doing some driving on the curvy back roads by my house. I started it up and it raised no problem. It has been cold so temp might be to blame, but if it is in fact a leaky sack, or pump, etc. Is this covered as part of the warranty? I would tend to assume that it must be since everything but tires and wiper blades are covered, but I wanted to check first before I took it in.

 

My guess is there is something wrong. I park my 2004 Allroad in temps well below zero all the time and it always retains the ride height. I used to drive a Mercedes S600 with an air suspension and it occasionally did this on very cold nights. Turned out it was a hairline crack in the system that only leaked on very cold days. Mercedes paid for it.

 

If there was a drastic change in temp, then it may have dropped because of expansion and/or contraction of the bags. Mine dropped a tiny bit the other day, but I think it's because the temp went from 60 to around 20 within 24hrs.

The answer to your warranty question is yes. The air suspension is covered under CPO. I had to replace one of the rear air springs due to leaks and it was covered.