The engine wiring can degrade because the insulating material falls off leaving the bare wire exposed. This can cause many problems depending on which wires are exposed and what they touch.
Mercedes-Benz 400SE Problem Reports
Most Reported Mercedes-Benz 400SE Problem Reports
Problems with the pneumatic system can cause closing assist and door lock issues.
A faulty mass air flow (MAF) sensor can cause erratic/rough engine operation and fuel economy issues. Since this sensor measures the actual amount of air entering the motor, when it fails, the engine control module (ECM) takes the wrong information and delivers incorrect volumes of fuel to the cylinders.
The brakes may begin to squeak at about the 50 percent wear point. This is due to the size and material used for the brake pads and rotors. The brake rotor surfaces become uneven, causing a lip to form at the outer edge. This will generally require replacement of the rotors when the pads are worn (pad life varies depending on driving style and terrain).
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 coolant leak may develop form the Radiator due to degradation of its plastic components. Replacement of the failed radiator will be necessary.
The cooling system hoses may fail unexpectedly. The hoses can look good on the outside, but the rubber can degrade and erode on the inside. If not carefully checked, the hoses can burst at any time.
The tie rod ends, idler arm, and/or drag link components of the steering linkage may wear prematurely. Please keep in mind the wheel alignment should be checked and adjusted when any of these items are replaced.
A vibration felt through the center floor of the vehicle can be caused by cracked and/or shredded driveshaft flex discs, resulting in excessive driveshaft movement. If not repaired, damage to the driveshaft center support bearing, transmission, or differential can occur.
High mileage vehicles may develop a transmission fluid leak from one or more of the oil seals.
Leaks may develop from the differential seals and/or cover on older or high mileage vehicles. Our technicians recommend a complete reseal of the differential unit when these leaks are addressed.
The bushings for the shifter lever wear out to the point where they break and fall out. This causes excessive movement (loose feel) in the shifter lever and a clanging-type noise when changing gears.
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.
A worn steering dampening shock can cause a fluid leak at the front of the vehicle. If a leak is noted from the dampening shock, our technicians tell us that it should be replaced.