Car problem reports
Problem with your car? See what our experts say or submit your own.
Most reported car problems
The front window sash brackets may break causing the window to come off track. Our technicians tell us that new brackets are available and can be installed on the old window glass if it is not damaged.
The turn signal switch may fail causing the hazard/turn signal flasher to continue to click even when the turn signal switch is off. Replacing the faulty turn signal switch will commonly correct this condition.
The engine oil pan gasket can develop a leak. Leaking oil may accumulate on the exhaust system resulting in a burning smell. Replacing the gasket should correct this leak.
The speedometer or other instrument panel gauge may begin to work erratically at times. Our technicians tell us that the instrument cluster must be sent to a repair facility to correct this fault.
A plugged AC evaporator drain tube can cause a water leak inside the car; usually near the front passenger's feet.
The intake manifold gasket may develop and external engine oil or coolant leak. In some cases, an internal coolant leak may occur causing coolant to mix with the engine oil. Our technicians tell us that operating the engine with a coolant/oil mix can result in internal engine damage. Replacing the intake manifold gasket should correct these leaks.
It is common for the fuel level sensor in the fuel tank read the fuel level incorrectly. The sensor must be replaced to correct the condition. Our technicians recommend having the complete fuel pump module replaced on high mileage vehicles.
A leaking axle shaft seal and / or PTU cover seal can cause transmission (red) or Power Transfer Unit (PTU) (brown) fluid leaks at the axle area. The axle shaft seal and / or PTU cover seal may be leaking and should be replaced as required.
Due to warped front brake rotors or variations in the thickness of the rotors, brake pulsations may develop. The best method to reduce pulsations is to use an "On the Car" brake lathe (as long as the rotors are suitable for turning). "On the Car" equipment can correct variations (or "runout") in the rotor surfaces because it also corrects variations in other components (e.g. the hub).
The automatic transmission may develop shifting concerns. On lower mileage vehicles, upgrading the software in the powertrain control module (PCM) and the transmission control module (TCM) may correct the problem. As the mileage increases, internal transmission damage can occur. Repairs could involve replacement of the valve body or a complete transmission rebuild. Whenever major transmission repairs are made, it is important to be sure the PCM and the TCM have the latest software updates to help prevent these issues from reoccurring.
The active body control system can leak fluid from numerous areas, including the tandem pump, hydraulic lines, struts, and/or seals. If it is not repaired, the vehicle ride height could drop too low and cause damage to the undercarriage.
Various issues with the electric power steering system may develop and could require replacement of steering column assembly.
The passlock sensor in the ignition lock cylinder may fail causing an anti-theft system fault and a no start condition. Our technicians tell us that the ignition lock cylinder should be replace to correct this condition.
Water can leak near the A-pillar, at the front edge of the driver and passenger side doors. An improved seal is available.
Coolant leaks coming from the underbody on vehicles equipped with rear heat/AC are common. The underbody hoses should be inspected as part of regular maintenance. If you drive on roads where salt is prevalent the problem is generally more severe. Some 2005 models are involved in a special service action, no government recall was issued.
Vehicles equipped with a 7-speed automatic transmission may develop a rough shifting condition, most commonly going up from first to second gear and going down from third to second or second to first gear. Our technicians tell us this is due to an internal component failure. Mercedes has released updated parts; the transmission will need to be removed and disassembled to complete the necessary repairs.
The speedometer or other instrument panel gauge may begin to work erratically at times. Our technicians tell us that the instrument cluster must be sent to a repair facility to correct this fault. The warranty has been extended on some of these units to 7 years or 70,000 miles.
Illumination of the Check Engine Light can be caused by a loose or worn gas cap.
Temperature blend and recirculation doors commonly fail, which can cause the AC modes not to change or the temperature to be different on the left and right sides. If replacing blend air doors, a recirculation door, a door link, or a sub-assembly housing, new heating, ventilation and AC (HVAC) sub-assemblies are available that improve reliability.
The Check Engine Light may illuminate with a fault code P1121 stored. It is commonly caused by a failed three way coolant control valve. Valve replacement is recommended if this occurs.
There are reports of failures of the CCRM or Constant Control Relay Module. The CCRM has relays and switches inside that control or provide power to the engine cooling fan, AC clutch (to engage the AC compressor), fuel pump and powertrain control module (PCM). Single switches or relays can fail internally causing a number of different symptoms including no start conditions (inoperative fuel pump or PCM), engine running warm due to inoperative cooling fan, or the AC might not blow cold air.
The cooler for the EGR valve can leak coolant internally, which causes white smoke to come from the tail pipe. Hot exhaust gases are cooled by the EGR cooler before being circled back into the engine.
The camshaft adjuster solenoid (which is related to the variable valve timing system) may fail or timing chain/balance shaft components may wear, resulting in illumination of the Check Engine Light and various drivability issues. Mercedes-Benz has released a service bulletin outlining specific repair instructions depending on fault codes stored.
The rear light socket plate may fail causing a brake light or other rear light to stop working.