MagicJack

I just got my E550 back after 4 months in a body shop due to a rear bumper collision. Talk about a painful experience.

The car drives like new but I've noticed an occasional humming noise from the rear.

I believe it is the airmatic compressor. Its subtle and I can only hear it on quite roads while I am driving less than 20mph.

Questions for others with airmatic:
1) Does anyone hear their compressor in their new E
2) How often does the compressor normally run.

I had the car preaccidnet for only a week and I don't quite remember hearing it before.

I've noted it once or twice during the beginning of a drive or at times when I raise the car.

E550

The air compressor comes on for a second or two when I start the car, or open the door. Other than that, I have not heard any noise from it while driving. I have noticed, however, that even when the car is parked/locked, the air compressor comes on every few minutes (initially after parking) and every few hours (after being parked for a long time) to fill-up the air pockets/shocks. I am "assuming" this behavior is normal.

However, please note that in the 4300 miles I have put on the car, only once did the right rear suspension crash (the air came out completely, after being parked at the airport for 3 nights), the air filled-up in a couple of seconds of turning the ignition on, and it has not happened since.

pmb600

I don't have a W212 (yet) however I can say that on my W211 with Airmatic I do hear it sometimes when driving if I have the radio off. The one thing I noticed about the W212 Airmatic vs. the W211 is that after you turn off the car and get out, the air seems to rush out quickly and you hear a whoosh. On the W211 the car settles a little more slowly and you hear a hissing sound for about 10-15 seconds while the car lowers.

DHI

I just noticed a bit of a whirring sound at that back at the car at slow speeds after one month of ownership. I will need to become more acquainted with it in order to give you a proper reference.
As for release of air after parking... sometimes I get a long hissing sound (10 seconds) and other time I get one big fat "PFFT"! I have not yet heard the compressor run after getting out (unloading the car).

jbean114

I echo the same above... I have not heard the compressors while driving, but do get the odd "ppfts" and other non-flattering noises upon getting in and out of the vehicle... Could just be my lactose intolerance though.

FYI: Only 3 months and 4K miles worth of review here.

RickP330

Open the trunk and have someone else start the car or switch it from Comfort to Sport mode and back. See if you can hear the compressor run and confirm if that is your noise. show it to your dealer and ask them to fix it. I believe the resivioir is on the Drivers side rear in the trunk. I assume the compressor is around there too.
Kind regards,
Rick

konigstiger

1 central reservoir
2 compressor
3 air spring
N51/3 Airmatic control unit

048597 “may” apply even though vehicle level has not dropped or warning not received (yet) https://mbworld.org/forums/3917691-post8.html