mark_avant

It's not constant, but I hear it every few minutes... It's not the suspension compressor, because when I change levels, I can hear it, and it makes a different noise... Anyone ever have a noisy fuel pump or anything like that somwhere in the back of their AR's?

Rhoomba

... sort of. In practice, it runs only when the pressure in the air tank falls below a certain range (interesting note: the compressor, in an effort to be unobtrusive, is designed to NOT run when the car is traveling less than 15 MPH, unless the tank pressure falls below a second, lower threshold).

The system uses air pressure all the time - not only when the car changes levels but also when the suspension is in normal operation more (eg, as it adjusts itself to different loads). All this while, the system uses existing air pressure in the reserve tank (which is also tucked back there on the driver's side rear). The compressor is simply designed to top the tank off when necessary (as described previously).

So - all in all, I'd be willing to bet that it is your air compressor that's buzzing... it's just one of those things that you need another AR owner to hear it to be able to say "Yup - that's your compressor, dude."

(shrug) HTH.

MtTAMar

always assumed it was the compressor. Noticed it running more often/longer in temps below freezing. Dealer could not reproduce the sound, so couldn't diagnose it.