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.Google+
Car Problem Reports
Mercedes-Benz CLK55 AMG Engine Performance Problems Due to Crankshaft Position Sensor Failure
Mercedes-Benz CLK55 AMG Problem
Average Mileage: 118,028 mi (87,000 mi - 180,000 mi)
Started fine when cold, but after 5 miles, when stopping at a traffic light, engine dies and will not restart.
Very embarrassing in stop and go traffic......car will start when cooled off, but replace that crank sensor ASAP.
Independent German car repair facility charged $350 to replace a $40 part in half an hour.
Will fix it myself from now on......
Same problem. $600 to repair at local dealership.
Visitor, 2002 Mercedes-Benz CLK55 AMG, 120,000 mi
Visitor, 2004 Mercedes-Benz CLK55 AMG, 91,000 mi
This occurred randomly and cost roughly $500 to repair at Loeber Motors
Visitor, 2001 Mercedes-Benz CLK55 AMG, 125,000 mi
This is a very common problem on the Mercedes.
The Crank sensors fail at around 100K miles.
The sensor itself costs around $40- to 120, but it is located in a very tight spot to get to...
LH side of the engine, down near where the transmission bolts up to it, and close to the exhaust system.
Many automotive shops charge outrageous prices to replace the crank sensor....
Visitor, 2002 Mercedes-Benz CLK55 AMG, 87,000 mi
car didnt start after i put gas in the car.. engine check came on and it was the crank sensor.. i brought a new one and had my mechanic put it in..