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.
Airmatic Pump Motor May Fail Due to Sticking Relay on Mercedes-Benz S430 4MATIC
Average mileage: 74,500 (54,000–94,000)
10 people reported this problem
it keeps hissing, just want to know possible solution.
2003 Mercedes-Benz S430 4MATIC 54,000 mi, Visitor
had mecurly mercedes put in new pump