Airmatic Deflation Mystery
03-15-2023, 08:29 PM
#1
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1987 Porsche 928 S4, 2009 Mercedes E350, 2011 Mercedes GL450, 2003 Mercedes ML350
Airmatic Deflation Mystery
I may have purchased front struts in advance of further diagnosing this problem but my 2011 GL450 is experiencing the following symptoms:
- Suspension sits normally when engine running
- Switch engine off with car doors closed and front deflates flat.
- Open the door before switching the engine off, suspension stays inflated in the front.
If I open the door and then turn the car off, the airmatic maintains height throughout the night. .
I assume the front strut left or right is not leaking if it maintains height for more than 8 hours.
Any thoughts?
- Suspension sits normally when engine running
- Switch engine off with car doors closed and front deflates flat.
- Open the door before switching the engine off, suspension stays inflated in the front.
If I open the door and then turn the car off, the airmatic maintains height throughout the night. .
I assume the front strut left or right is not leaking if it maintains height for more than 8 hours.
Any thoughts?
03-16-2023, 12:23 AM
#3
Set the car to the highest setting see if you get the same result. Just be away, the higher the pressure in the below, the more likely the hole is going to grow quickly and suffer rapid deflation.
03-16-2023, 10:08 AM
#4
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1987 Porsche 928 S4, 2009 Mercedes E350, 2011 Mercedes GL450, 2003 Mercedes ML350
Just went out and looked at it. Height never changed after last 12 hours. Took a tape measure to confirm it too.
Either way, the struts are coming off and new Bilsteins are going in once the weather cooperates. I have a bad axle too on the driver side. Axles are also on the to do list at the same time.
Last edited by Uranium238; 03-16-2023 at 12:20 PM.
03-16-2023, 03:30 PM
#5
MBWorld Fanatic!
Well, it’s not your bags. So I don’t think you need to go ahead and replace them unless they are an off brand Chinesium crap shoot, there is something going on with your ECU giving a signal to deflate.
so if the suspension will deflate overnight without you opening a door while it’s running how are you getting out of the car?
it might be interesting to note what the residual pressure in the system is, if you did open the door. What might be going on is that the car is being tricked into a keep alive circuit and is inflating the front struts overnight, de depleting, the battery, and the central pressurized air Reservoir. Neither situation’s is good.
so if the suspension will deflate overnight without you opening a door while it’s running how are you getting out of the car?
it might be interesting to note what the residual pressure in the system is, if you did open the door. What might be going on is that the car is being tricked into a keep alive circuit and is inflating the front struts overnight, de depleting, the battery, and the central pressurized air Reservoir. Neither situation’s is good.
03-16-2023, 03:41 PM
#6
MBWorld Fanatic!
I may have purchased front struts in advance of further diagnosing this problem but my 2011 GL450 is experiencing the following symptoms:
- Suspension sits normally when engine running - CAN YOU hear the compressor running?
- Switch engine off with car doors closed and front deflates flat. HOW LONG DoeS iT TAKE TO DEFLATE? Instant or overnight?
- Open the door before switching the engine off, suspension stays inflated in the front. HOW LONG for? Does it sag after a few days?
If I open the door and then turn the car off, the airmatic maintains height throughout the night. .
I assume the front strut left or right is not leaking if it maintains height for more than 8 hours.
Any thoughts?
- Suspension sits normally when engine running - CAN YOU hear the compressor running?
- Switch engine off with car doors closed and front deflates flat. HOW LONG DoeS iT TAKE TO DEFLATE? Instant or overnight?
- Open the door before switching the engine off, suspension stays inflated in the front. HOW LONG for? Does it sag after a few days?
If I open the door and then turn the car off, the airmatic maintains height throughout the night. .
I assume the front strut left or right is not leaking if it maintains height for more than 8 hours.
Any thoughts?
Last edited by Max Blast; 03-16-2023 at 05:14 PM.
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EmilyMB (03-17-2023)
03-19-2023, 01:51 AM
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1987 Porsche 928 S4, 2009 Mercedes E350, 2011 Mercedes GL450, 2003 Mercedes ML350
Driver side bag had failed. The leak was toward the top and would seal when the bellow folded during airmatic reset by opening the door.
