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.
Car problem reports
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Most reported 2009 Mercedes-Benz CLK350 problems
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 heating, ventilation and AC (HVAC) heater box is susceptible to mildew buildup. This can result in a musty odor from the HVAC system, most noticeable when the system is first turned on.
The sway bar end link joints may wear and cause a knocking noise over bumps. Loose or warn links should be replaced to correct this type of noise.
Computer control modules for the seats and doors, the CD changer, and the brake lamp switch tend to fail.
Going over large bumps in convertible models may cause the roll bar to deploy, rendering the roof inoperative. Special tools are generally required to return the roll bar to its stowed position.
Ball joints can wear out prematurely, causing wear in the tires.
The crankshaft position sensor may fail. Symptoms of this are: The engine will crank—but not start—especially when the engine is warm. The car may start again if it is left to cool off, but it may run roughly or have poor performance. Communicating these specific symptoms to your technician can save diagnostic time.
Cup holders in the dash are known to break requiring repair or replacement.
A repetitive clicking noise from behind the center area of the dash panel is usually caused by a broken stepper motor actuating arm. The actuating arm controls the direction of air flow in the climate control system. Disassembly of the center console will be required to access and change the broken arm with the updated, reinforced part.
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.
Torque thrust bushings in the front suspension may crack and leak oil, this causes steering alignment problems and excessive tire wear. Another symptom of a worn bushing is a clunk or thud noted when turning, on hard acceleration, or hard braking.