1991 Mercedes-Benz 420SEL Repair and Maintenance
A guide to problems, costs, maintenance and repair for your 1991 Mercedes-Benz 420SEL
- Bad Switch/Blower Motor Resistor Assembly May Cause Inoperative Heater Blower Motor
- Stuck Idle Air Compensator May Cause Too High/Too Low RPM
- Replace timing chains/guides every 100,000 miles
- Rubber boot connecting throttle body to intake manifolds may crack
- Valve Stem Seals Wear and Cause Catalytic Converter Failure
1991 Mercedes-Benz 420SEL Problems
Other than a defective motor, a bad switch or blower motor resistor assembly can cause an inoperative heater blower motor.
It is not uncommon for the idle air compensator to get stuck in one position, resulting in the engine idle speed (rpm) being too high or too low. Replacement of the failed compensator may be necessary to correct this concern.timing chain and timing chain guides wear; they should be replaced every 100,000 miles.
1991 Mercedes-Benz 420SEL Questions
where do I spray starter fuel? how do I find air intake pocket?
Had old battery so replaced it with new one. Checked alternator and it is good. Will start with a jump and after freeway drive. Will not start after it sits overnight next day without another jump?
1991 Mercedes-Benz 420SEL Reviews
great car!! still a head turner after almost 20years.. have owned my 91 420sel now for 5 years and still performs, looks, handles and drives like brand new with only 150k...maintenance can be costly..GREAT Highway cruiser..no cup holders :( .. last of the big(long) dinosaurs..
THE HANDLING REALLY NICE THE VENT DOES NOT OPENING TOOK ME FOR AWHILE TO GET AC ON ALMOST 1991 S CLASS HAVING PROBLEM WITH CRUISE CONTROL SWITCH IT'S DOESN'T WORKING SOME TIMES DOES.I'VE GOT BAD FUEL PUMP ON BOTH LEAKING TO REPLACED COST ME $500.000.