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 E350 Airmatic Pump Motors May Fail Due to Sticking Relays
Mercedes-Benz E350 Problem
Average Mileage: 59,595 mi (15,000 mi - 88,000 mi)
Visitor, 2006 Mercedes-Benz E350, 65,014 mi
Turned off the car and had a noise coming from the engine. Pulled the wire off the Airmatic Pump noised stopped.. Going to look at more when car cools down
Visitor, 2007 Mercedes-Benz E350, 44,000 mi
Problem: The Air Pump relay sticks.
Symptoms: Whining noise and the car won't start.
SOLUTION: I fixed it with a hammer! I banged on it (Not too hard) around the sides of the pump and tried starting it again. The car started perfectly and sounded normal.
Cost to Fix: $0.00 :)
Visitor, 2010 Mercedes-Benz E350, 15,000 mi
Dead battery would easily jump start took to dealership unable to find source of draining. Charged battery no longer a problem been 2 wks. After washing car last week heard sound of air discharging near front tire for a few minutes intermittingly figure it could be this suspension issue. the sound I heard makes sense. Now have check engine light on will bring to dealer to read code and will dicuss the suspension issue.
Visitor, 2007 Mercedes-Benz E350, 67,900 mi
Heard the weird noise near the right front tire after the car was off. The NEXT time I started the car, the malfunction message was on. Car runs perfect, drives smooth-no issues at all. Shocked that the average mileage of this issue is the EXACT same as mine. Wondering how much THIS will cost to fix.?