Good Morning,

I have replaced the air pumpabout ayear ago in my Airmatic system on my 2000 S500. Everything was working fine up until now.
The last time I took the car for a ride after I stopped the car and the engine and took the key out the air pump was still running. I hear air going a way and the pump still running. It had a bad burning smell and every now and than gave some shaking loud noise. I had to disconnect the battery in order to stop the pump. The next morning battery still disconnected and the car did not lower at all, so I think there is no leak. Could it be a bad hight sensor?[&:]
HELP PLEASE!!!!!

 

a bad relay for the pump is probably the case. relay O in the fuse box right side under hood. the relay sticks then burns up the air pump motor then blows the fuse also.

 

Thank You very much! I am going to get an other relay tomorrow.

 

Autohausaz.com is a good place to get MB parts.

 

is the pump pretty noisy, I know in our denali you can hear when that thing kicks on but I have never heard it in our s500, I dont drive it verymuch...would like to make sure that this is not always on, as I have read horror stories about airtronic issues in these cars

 

Tthat's good. You are not supposed tohear it. It should only run when the engine is on and the system is scanning the hight of the car and according to that info the air pump can adjust the ammount of air in the struts.You can try every now and than with the engin on to get closer to the rightfront, underneath the headlight, because that's where the air pump is located. The sound it makes is low, but noticable. Sounds just like a fishtank air pump(if you ever heard that!?!?).
It's loud enough to hear it clearly with the engine running, so sure enough you will hear it when the car is shot down. And it start giving a burning smell, which by the way goes also inside the passenger area thrue the A/C, so it's kind of easy to recognize if there is a problem.