im having an air suspension issue >> i hear what im assuming is a compressor kicking in when while i drive or when i start the car... when the car has been turned off any consideraable amount of time my back suspension is lowered..when i turn on the car I wait until the compressor turns off and the back suspension has risen<<
air suspension issue on 2001 Ford Expedition
The most likely cause of your concern is leak rear air shocks. Inspect the shocks where the rubber folds inside itself, if there is cracking, spray a soapy water solution on the area while the air suspension is running. If there is leaks identified, shock replacement is required.
I have same problem but if I turn them off in the trunk it takes about 3 dayes for them to leak down.