Air Strut, Compressor, or Sensor?
 

Hey everyone,

So after a fun winter of battery and coolant (valley pan replacement) issues, here is my latest. When my 07 4.8i with active suspension sits for more than an hour now, my rear suspension completely deflates.

Thing is this happens much more quickly if I am on an uneven surface and sometimes only on the drivers side. So I am looking at either a strut, the compressor itself, or a sensor which is bad. I have no DSC errors at all so as long as I wait for the car to reinflate the suspension before driving I am good to go.

Question is, how does this system really work and how can I eliminate fail points? Anyone have any good guidance on how to approach this? I have looked around the forums and only see the replacement threads but no real diagnosis.

Any help is appreciated and I look forward to Ard's super smart response telling me I am a horrible person for asking :)

You're a horrible person for asking.

You most likely have a blown airbag with the second one very close to fully failing as well. Pretty simple fix if you're a do it yourselfer

^Beat me to it. ;)

Agree about the airbag. The DIAGNOSIS is to get under the car with some soapy water in a spray bottle.

Good news though- by catching this early you may have saved the airpump...after a while, with continuous running, it burns out. A few recent posters have come along seeking info only after the car is fully deflated (ie it never 'comes up') and find that not only was there a leak in a bag, their continued disregard caused the pump to fail too!

Thanks guys.

So over the weekend, no suspension leakage at all. It was a bit warmer out which seems to matter. I have an appt tomorrow to have my shop take a look. I am assuming that either the bags are shot or during this winter my car got hit and I had to have both axles replaced along with my rear passenger side wheel and various other items. Thinking it is possible they may not have hooked up the compressor properly and a bad connection my leak when very cold and not when warmer. I guess we will find out!

Thanks for calling out the compressor concern, good call, mine is working like a champ and I would like to keep it that way.

Oh....

Yeah..... Long story short, don't drive from Chicago to Philly to do a charity ride and expect people in Philly to obey what a red light means..... T boned, 3 months and 15k worth of repairs, I finally got my car back.