I am sure you have guessed by now that this is not a new problem on the W220, firstly check the top of your front struts for cracks, there is a modification for this problem.

If air leaks occur then the pump tends to work overtime and also puts undue heat into the relay, both can fail. So check for leaks first or you may end up burning out your new pump.

If you do a search on this subject you will find a LOT of threads:thumbsup:

 

This might be out of bounds, Have you checked your fan to see if that is the noise you are hearing when comes on and off? Main fan bearing or the remote motor. Just a shot in the dark.

 

its could be the relay. Happened to me before

 

The only thing with the relay is it stay's on or it does not, That is how they work will not fluxuate. They recieve info to open circut or close.

 

Merc786, did you have your airpump replaced together with buffers and pump air filter? If not, then most likely old pump buffers are the reason of the noise.

 

Currently the pump is not on constantly so therefore I assume it is not the relay!

The pump seems to come on for about 2 minutes when i turn the car on and drive but turns off if i press the brakes and then as soon as i continue to drive the pump will turn on again for a total of roughly 2 minutes - I am quite confident that this noise is from the air pump although I cannot be 100% sure whether it is definately the airmatic pump comes on again later or if it is something else that is vibrating!

Nikolas - I have not heard of the buffers or air pump filter until now, can you tell me anymore about them ie. what do they do and where are they located?

Also, could anyone tell me if the pump is supposed to only turn on when the car is started for a short period of time or whether the pump will continuously pump air as and when it is required to adjust the suspension?

Finally, does anybody know for certain if the ride height must be re-set/calibrated after a new pump is fitted? After speaking to an independant mechanic who is apparently a bit of an expert on the Airmatic suspension, I was told that this is not the case although some people on this site and Mercedes are convinced that calibration must be done for the new pump to work properly - can anybody shed any light on this?!?!

Btw, thank you for comment so far!

 

You should and I recomend you have the ride height calibrated so snesors all know where they are. Second I never heard of buffers or filter either. Third if you hear the noise from inside the vehicle with windows closed that is probably your abs system.
The pump comes on when needed to adjust susp. automaticly.

 

So Gammaess, you think I should definately have Mercedes reset/re-calibrate the ride height?

I was told by independant mechanic that the noise may be ABS pump too so more than likely that is the case.

 

Myself I would have a shop recalibrate the ride height, It does cost but not alot and then you know that all sensors are good because they communicate with the computer and everything is doing what they are supposed to and you bought the vehicle for that amazing ride.
It is just a pain in the ass.

 

I might sound stupid, but how do you know if your pump is working or not. I was playing in the car with ride hight and could not hear anything more than normal noises ???

 

That is normal for good or new pump - you almost can't hear when it is working. The sound of working pump is obvious when the pump is worn. After I had my pump replaced together with buffers - I can't hear it neither.

Speaking about buffers and air filter - please, follow this link: CATALOGUE /tell me if this link doesn't work/

A2203270830 (needed 3 pieces), A2203270930 (needed 2 pieces) - these are the part numbers for rubber buffers;
A2203200069 - this is the pump air filter.

 

That still happens after you have had the pump change? If so I would without doubt take it in to be looked at by someone who is experienced with MB and has star diagnostic's.

 

Once again...another issue with Airmatic!

About a month ago my airmatic pump started to make a hideously loud vibrating/rattling noise, there was nothing on my display to indicate there was any problem and the suspension seemed to go up and down OK.
The noise was continuous and would only stop briefly(2/3 seconds) when i pressed the button on my dash to raise the height.

I had a local independant garage look at it who found that the cover for the pump was hanging of, they cleaned the pump and put it back together and told me it was fixed...unfortunately, this was not the case and I found that the pump continued to vibrate although the noise was not as loud!

Eventually, I decided to replace the pump with a new one from Mercedes although I got the local garage to install it. Once again I was told that the new pump was working fine and again found that this was not the case. As far as I can tell, the suspension seems to work OK ie. it goes up and down BUT the airmatic pump comes on for a few minutes when I start the car and continues to turn on every so often!

Can anyone help or offer any advice whatsoever???

IT THE BUSHINGS THAT HOLDS THE
COMPRESSOR THEY ARE BAD. I HAD SAME PROBLEM

 

I have this same problem after a mechanic removed the air compressor to install a distribution block. I had a shop reinstall the air compressor with new hardware(so they claim)
But I still have the rattling noise every time I start or go up and down hills in the road.
Some days it’s louder and lasts longer than other days.

 

You just bumped a 12 year old thread

 

LOL, I should start doing what another Forum does and lock the Necro Threads when this happens

 

That can depend. I myself have updated necro-threads when I've found new info on solving a problem.

 

And that my friend is exactly why I do not lock them

 

At least KidRichs550´s first post was to contribute something and not to ask and run as usual!

 

Installing the Airmatic compressor correctly is a pretty fiddly job, and mount assembly is not intuitively obvious. It is a combination of springs, rubber mounts and bushings. Putting it together exactly as it came apart might not work, if it has been put together incorrectly already.

 

Reading these old threads ,It´s funny how little many of the owners know about their car.Of course,it is easy to say this in the year 2022,when we have The Encyclopedia and all..