An engine Oil leak may develop from the PCV vent housing on the valve cover and/or the inspection plate on the front of the engine.
Mercedes-Benz S500 Problem Reports
RepairPal Verified Mercedes-Benz S500 Problem Reports
The rubber bond in the harmonic balancer can decay, which causes the balancer to move and work its way toward the timing cover. If the balancer comes into contact with the timing cover while the engine is running, it will fracture and damage the cover and potentially other surrounding parts. The harmonic balancer should be inspected at every service.
The electrical connector at the automatic transmission may leak fluid. Over time leaking fluid could migrate through the wiring harness and damage the transmission control module. If that happens a new harness and control module may be necessary to correct the problem.
The electronic throttle assembly may suffer an electrical failure. It is often cheaper to send the valve to a service center for repair that to purchase a new part.
CD changers, command units, voice control units, PSE units, and Tele Aid units are prone to failure, especially in early models.
Problems with the pneumatic system can cause closing assist and door lock issues.
A coolant leak may develop form the Radiator due to degradation of its plastic components. Replacement of the failed radiator will be necessary.
High mileage vehicles may develop a leak from one or more of the transmission oil seals.
A fluid leak from the front of the vehicle may be a result of a worn steering dampening shock. Our technicians tell us that if a leak is noted from the dampening shock it should be replaced.
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.
As brake fluid becomes dirty over time, it can cause a failure of the anti-lock brake system (ABS) modulator assembly. Our technicians recommend a complete brake system flush every two years to help prevent this issue.
A cracked or broken heater core outlet housing can cause a coolant leak near the bulkhead (firewall). Our technicians remind us that coolant leaks should be repaired in order to avoid overheating the engine due to coolant loss.
One or more of the following steering linkage components may wear prematurely; tie rod ends, drag link, or idler arm. Our technicians remind us the wheel alignment should be checked and adjusted if any of these items are replaced.
Internal and External engine oil & coolant leaks can develop from the head gasket and/or timing cover gasket; these leaks should be repaired before the engine oil and coolant intermix which can result in severe engine damage.
Vehicles equipped with a 7-speed automatic transmission may develop a rough shifting condition, most commonly going up from first to second gear and going down from third to second or second to first gear. Our technicians tell us this is due to an internal component failure. Mercedes has released updated parts; the transmission will need to be removed and disassembled to complete the necessary repairs.