Air suspension issue
 

I have an 2006 A8L. I recently noticed the rear driver side tire bottom out on the suspension. If I open an close the door the air compressor will bring that tire up and every thing is fine. This is not an everyday occurance but is happening more often.

Could this be an air leak in the strut or could it be a leveling sensor issue?

More Details
 

I have been observing this vehicle for the past couple of days. Yesterday I drove the car to work let it sit for twelve hours (checking it periodically) and there was no movement. Went to movies and dinner, arriving back home around eleven and still no problem. This morning around five the left rear tire was down, pretty much under the wheel well, I could not get the car to lift so I guess it lowered the passenger rear to compansate. After arriving at work both rear tires where down, and the minute I shut the car off and shut the door both rear tires are raised. The car has been sitting for about six hours and there is no movement from the rear.

Sounds like there is an air leak on one of the rear springs, it gradually gets worse until it won't raise the car at all. The pump will work overtime to inflate but has a auto switch off for over heating, at which point the car will bottom out.

Also it could be the control module or the air lines. You will need a VAG COM analysis and then step by step elimination of possible causes.

How many miles on the car?

There is 115,000 on the car. I would love to find someone with a Vag Com in Columbia, SC.