S211 suspension sinking

[Mb-enthusiast]

Hi all,

My s211 2009 e220 has started sinking regularly at the rear. Both sides are sinking rather than just one side. I keep reading about a t-piece that is prone to failure and could cause this issue but I can’t find a part number for it. Is anyone able to help?
Thanks in advance

 

[Blobcat]

Hello and welcome,

Cracks in the rubber airbags are very common. Lots of threads on here about them

 

[Wearsafoxhat]

I think the T piece you refer to is a valve block and am presuming that you have the rear only set up, not the switchable mode system.
I would check for leaks along the lines and at the compressor output. Leaks in air bags are also common as above, iirc, a leak in one will cause the system to lower the other one.
Does it rise once you start the car. Does the pump continue to run or run often as if compensating for a leak..

 

[Mb-enthusiast]

Yes, car rises when engine is running. I think it does run often as I received a malfunction warning on a long journey last week.

 

[Uncle Benz]

The s211 has electrical solenoids at the top of the air spring that close it off to the air supply pipes, so you can rule out the pipes. The air springs themselves are the most common failure point, usually followed by the compressor if it’s been overworked on leaking air springs. The only thing common to both is the level sensor. It’s in the middle, above the diff and connected to the anti roll bar. The link rod can rust right away, so worth a check. My gut feeling is the air springs, but it’s hard to be sure on description alone

 

[MB 212]

Hello and welcome,

Cracks in the rubber airbags are very common. Lots of threads on here about them

I have a weird one. Suspension sinking intermittently. Came home today, left the car unlocked, 1/2 hr later the car was down on the bump stops… Started the car ..did not move it, it came up to normal location, stopped the engine but I locked the doors strait away. The car is still after 8 hrs holding the high level. Some mornings the same high level, other mornings it’s down. Drives me nuts as I do not know what to replace…..

 

[Uncle Benz]

W212? It’s most likely the air springs. They leak where the rubber is crimped to the plastic blocks. They can settle in a slightly different place when re-inflated and not leak, but as time goes by they get worse and worse. If it was immediately going down the same each time I’d be looking for chafed pipes on a 212 (they are different to 211), but what you describe says air springs to me.

 

[TheFridge]

I have a weird one. Suspension sinking intermittently. Came home today, left the car unlocked, 1/2 hr later the car was down on the bump stops… Started the car ..did not move it, it came up to normal location, stopped the engine but I locked the doors strait away. The car is still after 8 hrs holding the high level. Some mornings the same high level, other mornings it’s down. Drives me nuts as I do not know what to replace…..

Same problem as mine. Did you sort yours ? I am going to tackle the air springs. Can someone here provide a link to the Arnott air springs ?
Thanks

 

[MB 212]

Hi all,

My s211 2009 e220 has started sinking regularly at the rear. Both sides are sinking rather than just one side. I keep reading about a t-piece that is prone to failure and could cause this issue but I can’t find a part number for it. Is anyone able to help?
Thanks in advance

 

[MB 212]

Mine 212 estate 2011 cdi behaves very strange when parked, and if it’s not level meaning if I park it outside the house one way and the rear is slightly higher than the front it can sit there for days ok not lowering the rear, but parking in the same spot the opposite direction it sinks. It drives me crazy as it indicates to me that there is no leak but something else governing the system. I know it sounds crazy but it is true.

 

[Uncle Benz]

Mine 212 estate 2011 cdi behaves very strange when parked, and if it’s not level meaning if I park it outside the house one way and the rear is slightly higher than the front it can sit there for days ok not lowering the rear, but parking in the same spot the opposite direction it sinks. It drives me crazy as it indicates to me that there is no leak but something else governing the system. I know it sounds crazy but it is true.

It’ll be the air springs. They can lean one way and keep the air in, but lean them the other and sometimes you can watch it sink

 

[malcolm E53 AMG]

Arnott are the go to replacement air springs reasonable quality are a reasonable price

 

[TheFridge]

I just ordered new Arnotts today for mine so hopefully that’s my issue too