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.
Mercedes-Benz 300E Problem Reports
Most Reported Mercedes-Benz 300E Problem Reports
A rough running motor or lack of power can be caused by a failed distributor cap or rotor, ignition wires (or their resistors), or valve cover gasket leaks. If the valve cover gasket leaks, oil can pool where the ignition wire resistor connects to the spark plug. The resistor can fail and the spark plug may not fire because of a short circuit through the oil.
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.
Due to wear of the internal drive gear, the speedometer can stop working.
A coolant leak may develop from the water pump. When replacing the water pump, the drive belt tensioner should be inspected and most likely replaced as well.
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.
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.
Internal and External engine oil & coolant leaks can develop from the head gasket and/or timing cover gasket; these leaks should be repaired before the engine oil and coolant intermix which can result in severe engine damage.
High mileage vehicles may develop a transmission fluid leak from one or more of the oil seals.
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.
The emissions air injection pump can seize, causing a loud squealing noise followed by smoke from the drive belt. If the engine is not turned off, the belt will break, turning on the alternator/battery warning light.
The bushings for the shifter lever wear out to the point where they break and fall out. This causes excessive movement (loose feel) in the shifter lever and a clanging-type noise when changing gears.