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.
2009 Mercedes-Benz GL450 Problem Reports
Most Reported 2009 Mercedes-Benz GL450 Problem Reports
An engine Oil leak may develop from the PCV vent housing on the valve cover and/or the inspection plate on the front of the engine.
As a way to increase braking performance, the brake pads and rotors are make of a softer material and may be in need of replacement after approximately 20,000 miles; owners should be vigilant about getting their brakes checked.
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.
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.
It is not uncommon to encounter premature failure of the anti-lock brake system (ABS) modulator assembly due to dirty brake fluid. Our technicians recommend flushing the brake fluid every two years in order to help prevent this problem.
An engine oil leak may develop from the oil level sensor. Replacement of the leaking sensor will commonly correct this concern.
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.