2011 GL450 - 135k miles, when I'm stopped at a light, the suspension will randomly raise up a few inches (happens maybe every third time I drive it). My wife insists this happens all the time, but I thought it was probably related to a slow leak. It started "deflating" at night so I replaced the front suspension today (both sides) and was surprised when it happened again. Is this a common occurrence throughout the life of the airbags?

This is my second suspension replacement. Replaced all 4 at around 80k miles.

 

A "few inches" is quite a lot. Have you measured that, or is just a guess? If you can better clarify that with some actual measurements it would be helpful. A few inches is not normal... to readjust itself slightly is normal.

 

I'd estimate it raises by 1-2". I watch the hood of the car go up against the backdrop of the car immediately in front of me. And it's always up, never down. Which makes me worry that it's compensating for loss.

 

That would be excessive, if it's actually that amount. However, the angle that you are viewing things at compared to the distance can be deceiving. It's quite possible that everything is OK and it's adjusting itself a normal amount - less than what you are "preceiving". Since you have no other symptoms, that would make the most sense. Otherwise, do a real measurement to find out for sure - and then we can go from there.

 

Dennis,

You're probably correct (that I may be exaggerating the distance due to the angle). It seems it happens only at stop lights (not at start up where I'd be able to measure it). For the moment I'll assume it's within the normal operation and keep an eye on it. I appreciate your taking the time to provide the insight. Thanks!

 

If it does it at stops while out on the road, it would do the same thing when you stop at home. Have someone standing by ready to measure. If you have an angled driveway, though, do it out on the street - just to eliminate variables.

 

Wife is right !!!
Normal behavior as car raises up after it has lowered itself while you drove 40+ mph before stopping at light

 

OP, is your car optioned with Advanced Damping System (ADS)? - if so you should have a lowering button.

Advanced Damping System has this feature, and the button is mechanized to lower the car 1" regardless of speed.

I am not sure that an automatic lowering feature exists in non-ADS equipped cars?


If the car doesn't sag overnight of after periods of non-use, your airbags seem to be in good working order and nothing to worry about.

If you hear your compressor running at all times, then it's compensating for a leak and there's definitely a leak somewhere.

Other than that I'd just keep an eye on the horizon and an ear out for excessive compressor run time.

Max

 

check if the air springs are leaking. I just got one of my strut replaced and Now the other side is leaking. And like you said it will go up and down randomly. I thought it was the valve block but spring leak is the bigger issue. Spray soapy water at the base of the strut that seem to get the most wear part of the bladder. Airmatic system is trying to keep up w the leak and it will push air in the bladder often.