The relay which turns the airmatic suspension pump on may fail causing the pump to run continuously. This can result in failure of the pump motor or a dead battery as the pump motor will continue to run after the car is turned off. Also, Worn airmatic pump mount bushings can causes noises in the front axle while driving on bumpy roads or a buzzing noise while the pump is running.Google+
Car Problem Reports
Mercedes-Benz E550 4MATIC Airmatic Pump Motors May Fail Due to Sticking Relays
Mercedes-Benz E550 4MATIC Problem
Average Mileage: 58,270 mi (38,000 mi - 85,000 mi)
Visitor, 2010 Mercedes-Benz E550 4MATIC, 38,000 mi
Often after the car has been sitting for a few hours on one side or the height on 1-3 sides are very high as if I selected the vehicle rise button..mind u this is the case prior to me even stepping foot into the vehicle. Also I constantly get the Malfunction indication warning to include a message which tells me to pull over, the vehicle is too low. I hear hard clicking noises when I ride over any rough road areas. I continuously hear the air pumps engaging. I can not quickly pull off after starting the car because usually one side is sitting close to the ground.
Visitor, 2007 Mercedes-Benz E550 4MATIC, 51,000 mi
dash signal says suspension malfunction and the car height will not go up.