Hi every one, I am new to this forum. I have a 2007 e 550 aromatic. I recently got rear brake job done by a local dealer . My rear wheel rotors and brake were bad so got a bosh rotor and a acknobo brakes for the same. Before the job was done aromatic was not showing any error and every thing was good. If i leave my car for 7 to 10 days rear wheel might drop but will come right back up after I start it . While the car mechanic did change the brakes , he called me saying that the rear wheel aromatic sensor arm was broke and air suspension was all over the place , this was weared as car was running fine and there was no error code . Any how I am not sure he did break that part in the process of repair or it was really broken and was stuck in one position . Any how I usually don't raise my car any how or change ride height frequently.

I did go ahed and give him ok for that and he charged 360 some $ for the same parts and labour included. any how car was looking good , brake noise was gone and then the most dreaded symbol came on airmatic sign and malfunction . I took the car back to him and then after keeping it for 2 days he mentioned that every thing looks good except the error code reading was air compressor running to long . He suggested to change air compressor for the same and 500 some $ for the same.

now when i park the car the light goes away but after running for few miles this will come back on . some time when I have just parked the care I will hear a short air leak hissing noice from rear as if the pressure sensor is letting some air go . the struts do not drop overnight but the rear height is little low i can tell . I m not sure what to do as to me it looks like until he changed the sensor arm every thing was all good . I love this car and recently got a glc and plan to keep this one and glc .

any suggestion what can be the problem , did he mess up the rear sensor for adjustment of the height . I think I should get it checked from mercedez as I am not sure how all of sudden the compressor will fail ?


also do you guys know any good mercedez benz machenic in cleveland area who can look at it ?

thanks

Rani

 

New sensor means you need to recalibrate the rear suspension. You'll need DAS to do so. Rear axle angles should be between -0.9 and -1.5 degrees (raise/lower using STAR) and the new sensor's voltage reading entered into the airmatic control unit using STAR. I've posted on this under "W211 suspension calibration". The procedure is here:
https://mbworld.org/forums/w211-amg/...ml#post7213168

More info here:
https://mbworld.org/forums/w211-amg/...ml#post6862688

You also mention a "hissing" sound in the rear; that indicates an air leak. The air leak means your air compressor runs too long and can overheat. The airmatic control module shuts the compressor off to save it from overheating. To find the leak(s), spray soapy water on the connection to the air spring, both ends of the rubber hose that connects the air spring to the external tanks, the "T" connection located under the car in the center of the rear subframe directly in front of the sway bar, and the connections located under the rear seat. There are multiple other connections but this will get you started. Do not rule out the possibility an air spring has a bad bladder that only leaks when the hole is uncovered/covered by the up and down movement of the air spring. If so, replace both air springs with aftermarket parts and recalibrate the rear suspension.