Mercedes-Benz S420 Repair and Maintenance
A guide to problems, costs, maintenance and repair for your Mercedes-Benz S420
Verified by mechanics, reported by drivers like you
Ask a mechanic in our community
Never overpay. Check prices with our estimator
Mercedes-Benz S420 ProblemsTransmission Oil Seals May Leak on High Mileage Vehicles
High mileage vehicles may develop a leak from one or more of the transmission oil seals.
Other than a defective motor, a bad switch or blower motor resistor assembly can cause an inoperative heater blower motor.
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.
Mercedes-Benz S420 QuestionsWhen I press the gas down my AC decreases. What could it be? (1 answer)
When I apply the gas it decreases everytime.
After sitting overnight it starts right up.