Air Pump for Self levelling suspension.

[Jetjockey]

Hello.

The rear suspension on my 2006 W211 E320 estate has been "settling" overnight ever since I've owned the car.

Yesterday I arrived home in the car, turned off the ignition and vacated the vehicle, to be greeted by a high pitched whirring noise emanating from the nearside front wing. The vehicle appeared to be level with no warnings or indications on the dashboard. The only way to stop this noise so far is to disconnect the battery!!

I'm currently assuming its the air pump for the self levelling rear suspension, but.....

The noise is coming from the nearside front wing, to the rear of the wheel, and just forward of a line dropped vertically from the door mirror... I thought the compressor was under the nearside headlight???

Also, I cannot find the relay or fuse for the compressor in the engine bay fuse box?
The vehicle does not have Airmatic suspension, only self levelling rear suspension.

I've plugged in a diagnostic machine and raised and lowered the rear of the car using a jack. The level sensor on the rear axle responds to this showing 2 volts and 55mm at its highest point but the noise continues!

Could somebody please help with this and suggest a possible cause, whether or not the compressor is in the wing behind the wheel, and where the pump relay and fuse are located so that i can isolate the pump.

Kind regards, Gerald.

 

[spenttherent]

Could be your alarm, you need to get the liner off and check it out

 

[Jetjockey]

Could be your alarm, you need to get the liner off and check it out

Hi there.

The alarm is working fine and on this vehicle is fitted up inside the drivers (offside) wheel arch. This is emanating from the Nearside wheel arch and is definitely a motor of some sort running.

Cheers.

 

[spenttherent]

Sorry about that, been a while since I had a 211

maybe this might help with the relay location

 

[Jetjockey]

Sorry about that, been a while since I had a 211

maybe this might help with the relay location

Thanks for that.
Its been a busy day and I've only just got back in, however..... It now appears that the noise may well be the rear windscreen wash pump.
I don't know why it should be running continually, and its not pumping any water, mind you it seems to be running flat out as if the impeller has sheared off. Also, when pressing the rear wash button, the wiper operates but no water sprays out!

The rear wash pump appears to be operated by a multifunction control module, but heaven knows where that is situated?

Many thanks, Gerald.