David M Grant

Hi everyone. I've had my 2010 for about two weeks. When I come out after the car has sat for more than 4 or 5 hours the passenger rear is sitting low. I start the car and it rises and then is normal, but sinks again over night. Advice?? Thanks

KEY08

Sounds like the air spring is shot. Could be other issues, but 95% of the time the spring has developed a leak. Test with SDS at the dealer.

thefisch

+1. How much is it dropping overnight? Are we talking less than half an inch or an inch plus?

David M Grant

well over 3 inches

thefisch

belarus27

Rear air bag shot? Common issue if this is the issue

Ungarisch

Before he goes and spends a grand on a new air-spring, I would double check the distribution valve under the rear bumper instead.

my 2011 E550 does the same thing but only under extreme weather (temp and humidity) change, like going from a 100*F dry day to a 55*F misty morning. Usually in the spring time.

I'm fairly certain that for me its the air spring distribution valve / solenoid that get stuck open as the car adjusts its bag pressure overnight to compensate for the barometric pressure changes.

my car (sometimes) fixes itself, as in the valve gets un-stuck after a cycling of the height (max>spot>comfort) a couple of times.

and again for me it only happens for a few times a year, and yet it does it for several day in a row and then never again for 9 months. I do live in SoCal where the weather does stay fairly consistent throughout the year.

distribution valves are a lot cheaper than air springs. If its not the valve then try and trace the leak with a spray bottle full of highly soapy water.