Problems with the pneumatic system can cause closing assist and door lock issues.
Resources for the Repair and Maintenance of your 1993 Mercedes-Benz 500SEC
1993 Mercedes-Benz 500SEC
1993 Mercedes-Benz 500SEC Problems
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).
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.
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.
Ports in the cylinder head related to the emissions air injection and EGR systems can clog; the cylinder head should be removed and the ports cleaned.
1993 Mercedes-Benz 500SEC Questions and Answers
The driver's side auto heating function does not blow hot air. The passenger side works fine. The Air Conditioning works fine on both sides of the car when using the automatic setting.