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 E500 Airmatic Pump Motors May Fail Due to Sticking Relays
Mercedes-Benz E500 Problem
Average Mileage: 89,000 mi (85,000 mi - 93,000 mi)
Visitor, 2003 Mercedes-Benz E500
I constantly hear noises both in the front and back axle. Also the ride is inconsistent each time i turn the car on and drive. Sometimes it would be softer and sometimes firmer. But I know I always have it set at the firmest suspension setting. The dealer never understand what I am telling them and each time they say nothing is wrong.
Also, twice the car has mysteriously had the battery drain on the car and no one could diagnose the cause.
Visitor, 2004 Mercedes-Benz E500, 93,000 mi
no heat in my car