When the engine is running, but the vehicle is not moving, a rattle heard from beneath the vehicle could indicate that one of the exhaust catalytic converters has failed. The substrate (the internal part of the catalyst that reduces emissions) can loosen and bounce around inside the canister section of the converter—the defective unit will need to be replaced. If this problem is ignored, the substrate can break down and reduce to a size that plugs the outlet pipe, which will cause a sudden loss in power.
Mercedes-Benz E320 Problem Reports
Most Reported Mercedes-Benz E320 Problem Reports
The electrical connector at the automatic transmission may leak fluid into the wiring harness. If not repaired, the oil will migrate through the wiring harness and damage the transmission control module. At that point, a new harness and control module may be necessary to correct this problem.
Water can damage the weight sensor in the front, passenger seat, causing the SRS (airbag) light to illuminate. There is an electrical component in the seat cushion susceptible to fluid damage. Any spills should be dried up immediately in order to try and prevent damage to the sensor.
The switch for the vanity mirror light above the sun visor fail; there is an updated switch for some models. On the remaining models, due to a redesign, the mirror "cassette" will need replacement.
The rubber bond in the harmonic balancer can decay, which causes the balancer to move and work its way toward the timing cover. If the balancer comes into contact with the timing cover while the engine is running, it will fracture and damage the cover and potentially other surrounding parts. The harmonic balancer should be inspected at every service.
This vehicle has sensotronic brake control (SBC). If the SBC light on the dash illuminates, have the brakes checked. If the SBC is not working, limited brake pressure is delivered to the front brakes, increasing the distance it takes to stop. The SBC hydraulic unit has a specific service life programmed into the control module; follow the manufacturer's recommended service procedure for proper maintenance of the SBC.
The release tab for the center console can fall off unexpectedly.
A coolant leak may develop form the Radiator due to degradation of its plastic components. Replacement of the failed radiator will be necessary.
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.
The mass air flow sensor tends to fail causing poor fuel economy and Check Engine light illumination. The engine air filter should be replaced when the mass air flow sensor is replaced; a dirty filter can allow debris to damage the new sensor.
The relay which turns the airmatic suspension pump on may fail causing the pump to run continuously. This can result in failure of the pump motor or a dead battery as the pump motor will continue to run after the car is turned off. Also, Worn airmatic pump mount bushings can causes noises in the front axle while driving on bumpy roads or a buzzing noise while the pump is running.
Due to age and sun exposure, the interior wood trim cracks and the finish gets a cloudy haze. Replacement if the trim would be the most common solution to the problem.
A vibration felt through the center floor of the vehicle can be caused by driveshaft flex discs, which crack and shred, causing excessive driveshaft movement. Not repairing these can cause damage to the driveshaft center support bearing, or, in the worst case scenario, damage to the transmission or differential.