Mercedes-Benz S420 Repair and Maintenance

A guide to problems, costs, maintenance and repair for your Mercedes-Benz S420

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Mercedes-Benz S420 Problems

Transmission Oil Seals May Leak on High Mileage Vehicles

High mileage vehicles may develop a leak from one or more of the transmission oil seals.

Bad Switch/Blower Motor Resistor Assembly May Cause Inoperative Heater Blower Motor

Other than a defective motor, a bad switch or blower motor resistor assembly can cause an inoperative heater blower motor.

Poor AC Performance Due to Refrigerant Loss

A refrigerant leak may develop from one or more of the following AC components: AC compressor, hose manifold for the compressor, or the evaporator core. The loss of refrigerant can cause poor AC performance. Our technicians tell us that proper leak diagnoses should be performed in order to determine the cause of any refrigerant loss.

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Mercedes-Benz S420 Questions

The heat works great but blower continues to run when the car is turned off? (1 answer)

Replaced the resister. Blower continues to run w.hen car is off. Have to unplug resister to shut off. Heat, air conditioning, blower and controls all work great, except for blower not shutting off when car is turned off.

When I press the gas down my AC decreases. What could it be? (1 answer)

When I apply the gas it decreases everytime.

how to bypass security car wont start. cranks but security lights flash and it inhibits it from starting. driver door not closing (1 answer)

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Mercedes-Benz S420 Recalls

Recall 96V058000
THE DRIVE BELT PULLEY ON THE ENGINE CAN DEVELOP FATIGUE CRACKS IN THE METAL AND BREAK. IF THE DRIVE PULLEY BREAKS, THE CAR WOULD NOT HAVE ENGINE COOLING, BATTERY CHARGING, AND/OR POWER STEERING.

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Mercedes-Benz S420 Reviews

the heater valve blowing warm air out of the vents and air condition works off and on. I was told if I by pass the heater valve Ill have good air condition but no heat until I replace the heater valve. rather have cold then heat right now. And I was told I can rebuild the heater valve, so 1, how do I bypass the heater valve and 2 is there a kit to rebuild the heater valve and where do I buy it?...
what cause my S420 Mercedes to lose power when accelerate from stop it sound like the plug missing fire it does it after driven a few miles stopping to a stop it get worse as I go along and stop at a red light or stop for any purpose.Sometimes when I shut car off and let engine cool down about30 to 45 minutes the car will run better.
heater dont work and shifter dont work it go in different spot drive is revers 3 is drive. what can i do.

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