Problem Reports
Problem with your car? See what our experts say or submit your own.
1994 Mercedes-Benz S420 Problems
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.
Premature Tire Wear Due to Cracked Lower Control Arm Bushings
The lower control arm bushings can wear and crack, resulting excessive movement at the control arm pivot point, leading to irregular and premature tire wear. Worn Ball joints can also cause similar tire wear symptoms. I some cases it may be necessary to replace the lower control arm, including bushings & ball joint to correct this concern.
Automatic car washes can damage head lamp wipers
The head lamp wipers are easily damaged, especially by automatic car washes.
Head Light Lenses Become Cloudy/Opaque
Due to exposure to the sun, lenses for head lights may become opaque (cloudy or hazy). This reduces the effectiveness of the lights. Our technicians tell us plastic polishes can improve the clarity of the lenses, but replacement of the lamp housings is the only way to regain the full intensity of the lights.
Coolant Hoses May Fail Unexpectedly
The cooling system hoses may fail unexpectedly. The hoses can look good on the outside, but the rubber can degrade and erode on the inside. If not carefully checked, the hoses can burst at any time.
Climate Control System Problems Due to Wear in Climate Control Buttons Contacts
The climate control system can fail or perform erratically due to internal problems with the climate control button electrical contacts. Replacement of the climate control assembly is commonly required to correct this problem.
Harsh Ride From Rear Due to Failed Dampening Actuator
Vehicles with automatic level control that ride harshly in the rear (no give in the suspension) may have one or both dampening actuators which have failed. It is commonly recommended the actuators be replaced in pairs.
Erratic Engine Operation and Poor Fuel Economy Due to Faulty Mass Air Flow Sensor
A faulty mass air flow (MAF) sensor can cause erratic/rough engine operation and fuel economy issues. Since this sensor measures the actual amount of air entering the motor, when it fails, the engine control module (ECM) takes the wrong information and delivers incorrect volumes of fuel to the cylinders.
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.
Throttle Valves May Experience Electrical Failure
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.
Closing Assist/Door Lock Issues Due to Pneumatic System Problems
Problems with the pneumatic system can cause closing assist and door lock issues.
Coolant Leak/Overheating Due to Radiator Leak
A coolant leak may develop form the Radiator due to degradation of its plastic components. Replacement of the failed radiator will be necessary.
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.
Fluid Leak From Front of Vehicle
A fluid leak from the front of the vehicle may be a result of a worn steering dampening shock. Our technicians tell us that if a leak is noted from the dampening shock it should be replaced.
ABS Modulator Failure Due to Dirty Brake Fluid
As brake fluid becomes dirty over time, it can cause a failure of the anti-lock brake system (ABS) modulator assembly. Our technicians recommend a complete brake system flush every two years to help prevent this issue.