My C200 has developed a fault with the airmatic suspension, no matter which mode is set the suspension is rock hard (maybe rear only difficult to tell) going over any uneven surface sends a jolt through the seat making it very uncomfortable. Suspect it's a damping problem, any ideas. No error messages and raising and lowering work ok.

 

my first thought is of the impending repair bill. the sales guy actually talked me out of airmatic because of costly repairs. Here's hoping it's just a glitch. Merlin the grandwizard!

 

Repair bill? It should be under warranty!

 

I've owned AirMatic cars exclusively since 2007. Definitely want it under warranty the entire time you own it. Doesn't sound like a failure in your case. Typically you'll come out one morning and the thing will be a low rider. Either an air strut develops a leak, or the compressor burns out, or both. It'll always give you a warning on the dash.

I'd get it on for a diagnosis on STAR. The ride height can be adjusted an inch or so by the software.

 

Only 2 years old so still under warranty, car in next week for service and hopefully repair.

 

I can raise and lower OK, ride hight looks correct, no error messages just no active damping so it's a bone shaker on uneven road surfaces.

 

Sensor or control unit failure would be my guess.

 

AirMatic is an air spring in place of a steel coil on an otherwise standard passively dampened hydraulic strut. Any active dampening is happening when impacts momentarily force air from the bag and the system reacts by quickly replacing the air from a pressurized reservoir. The effect is a momentary "give" in the stiffness of the strut/bag assembly as the air is vented.

A sensor failure will both throw an error and make itself obvious by dropping the affected corner up front, or the entire rear. A controller failure will also throw an error and won't respond correctly, or respond at all, to the lift command.

If the ride height is level at all corners, the car responds to a lift command and to agility commands and there are no warning messages between the speedo and tach, the system is functioning normally.

 

Except in my case whichever agility mode I'm in the suspension feels rock hard, harder then sport mode. Driving at night as well as being shaken about on poor roads you can see the effect on the headlight beam bouncing.

 

Forgot to add, when I first had this problem it was intermittent and could be corrected by switching off ignition and re starting.

 

Has it been in to MB for a diagnostic?

 

As earlier post service etc. next week

 

If nothing comes up on the scan, put the SA and tech in the back seat and take them around the block.

If you're outside the car and start from the raised (lift) position, then toggle Agility thru Comfort/Sport/Sport + can you see the car lowering itself? I have an AirMatic car too. Take a pic of the gap between the top of the rear wheels and the fender lip at each setting and I'll see if it's the same on mine. If it's able to raise and lower I wonder if you don't have a blown strut cartridge in the rear.

 

I though the dampers were magnetic? The air springs just being for well the spring function.

 

Hmm thought so.. Mb's own literature conflicts with your facts a bit..

https://www.mercedes-benz.com/en/mer...ension-system/

 

for info only..
https://w220.ee/Airmatic

 

In what sense? No mention of magnetic anything. A variable air spring on a conventional hydraulic strut.

 

Were you able to get any pics of the various ride heights on your car?

 

Had the same symptoms on a C400. Compression had to be replaced.

 

Compressor?

 

Fat fingers and autocorrect, sorry. Compressor, yes.

 

In the 220/221 the compressor failure usually came as the result of an air leak in a strut. The leak caused the compressor to have to run continuously and burn itself out. Was yours just a straight compressor failure or did you need a strut too?

 

Just the compressor as far as I know. I can hear it running and I know it wasn't running constantly before they replaced it.

 

Yeah there's a reservoir that it uses to accumulate pressurized air so it can be shot on command into the air springs as needed.

Normally the compressor runs for short bursts to top off the reservoir. I've never had one just go bad like that but any things possible.

 

It states variable dampers?