Other than a defective motor, a bad switch or blower motor resistor assembly can cause an inoperative heater blower motor.
Resources for the Repair and Maintenance of your 1991 Mercedes-Benz 420SEL
1991 Mercedes-Benz 420SEL
1991 Mercedes-Benz 420SEL Problems
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.
The timing chain and timing chain guides wear; they should be replaced every 100,000 miles.
The rubber boot connecting the throttle body to the intake
manifold tends to crack. This can cause hard starting, rough or erratic
idle, and engine performance problems.
Valve stem seals may wear and cause the engine to burn oil. this can contaminate the catalytic converter and cause it to fail.
1991 Mercedes-Benz 420SEL Questions and Answers
i need a repair manual for changing the timing chain system
how do you test the fuel injection system? If the transmission will not go in reverse will the trans have to be rebuilt?
I cant find a manual anywhere for my 1991 Mercedes 420 and am trying to find out what the flywheel torque specs are. Any help is appreciated.
Looking for the low pressure port to recharge the AC, but don't know where it is located under the hood. Would be really helpful if someone can provide a picture to pinpoint the location....
The low fuel warning light comes on at random once the tank level goes below 50 percent. Is the problem electrical or is it related to a float inside the fuel tank? Can this be resolved without h...
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.