Mercedes-Benz E420 Problems
RepairPal has identified the most common problems with the Mercedes-Benz E420 based on complaints from actual vehicle owners. We'll tell you what the problem is and what it'll take to fix it.
Due to wear, high usage vehicles can experience ignition lock and tumbler failures. The ignition lock cylinder will generally require replacement to correct this concern.
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.
The sunroof may not work correctly due to failed components as a result of age and wear. Repairing a sunroof can be labor intensive and very costly.
Ports in the cylinder head related to the emissions air injection and EGR systems can clog; the cylinder head should be removed and the ports cleaned.
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.
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.
One or more blend door vacuum actuators may fail resulting in the incorrect output temperature from the HVAC system. Failed actuators will require replacement to restore proper HVAC operation.
Leaks may develop from the differential cover and/or seals on high mileage or older vehicles. Our technicians recommend a complete reseal of the differential unit if these leaks are addressed.
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.