Dato55

So I'm walking to my car today about to go to work and I noticed all 4 corners were sitting low, the last time it was driven was the night before so it's not like it sat for a while and I start the car and it says car to low so I just press the raise button and it goes away, but I am starting to get scared that the air matic is about to go, if it's all 4 corners would this be air pump related? And also once in a while the car makes a very loud noise, sounds like a pump that's about to explode when it turns on and it shakes the pedales when activated, does anyone think it's air pump related?

Plutoe

Could be all sorts of things---find a shop that has the applicable diagnostic equipment to answer your question, however if you see sheep grazing out back---drive by!!

PS: If I told you its gotta be a pump---what would you do next!!

Dato55

I would replace the pump lol

cal1

Have a peek at my thread https://mbworld.org/forums/w211-amg/...ic-thread.html

Listen to the video and decide if your compressor sounds sort of like mine. Mine could be an extreme example.

Do you know anyone with DAS/Xentry (STAR) that could help you out. You can see from the screen shots in my thread how nicely the software reports the fault and even tests the pump.

Another option. Have the dealer pull codes for you. Bring your codes back to the forum and folks will help.

Finally, I am just learning about this stuff and far from a expert. Also, I have an ML with Airmatic issues, but the systems are very similar. One thing I found in doing research is the control unit (N51 for ML not sure if same for E) can fail and cause the pump to stay on too long and burn itself out. If I am not mistaken, there are other components that could also cause the pump to stay on too long. That it one reason why it would be good to get all faults.

One last thing, again according to my research when replacing the pump, it is a good idea to replace the air filter for the pump and also the relay.

cal1

Hey Dato55

Forgot to mention, I found this link was good at explaining a bit about airmatic issues. http://www.mercedesmedic.com/air-sus...isit-workshop/

Dato55

I have a video of the noise if only I can find out how to upload it.

cal1

^ freaking 55ks are noisy on a good day. I can't tell from your vid. Hopefully someone else can. The pump is behind the front bumper on the right (usually passenger) side. You might try recording the sound again. Maybe have someone raise the car so you know the pump is active when you record.

Not sure how other people do videos. I upload to youtube and then link.

Dato55

I will try to see if I can get a better video but hopefully it's the pump because that's a nice and easy fix

kajtek1

In W211 air compressor is behind left headlight.
When I rebuild my compressor, I install a pressure gauge what allows me monitoring the system.
The system has a program that prevents compressor burn out. In case of malfunction, the compressor will run for 2 minutes, than computer will shut it off for about 5 minutes and try again. Had no chance to make solid record, but after few unsuccessful attempt the light comes up.
Since OP had suspension drop overnight and it lifted fine with engine restart, it can't be compressor.
My observation is that poorly design drier allow lot of water in the system and water can fool the precision valves.
I would start with new filter and drier reconditioning.