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.Google+
Car Problem Reports
Mercedes-Benz E500 Engine Performance Problems Due to Crankshaft Position Sensor Failure
Mercedes-Benz E500 Problem
Average Mileage: 87,389 mi (60,000 mi - 104,335 mi)
I drove the car to work 32 miles parked it for 5 hours, went to lunch started OK, Parked it for about 1/2 hour than got into the car and cranked but would not start. Let it sit for about 15 minutes and it started and the CHECK ENGINE Light went on. Took it to MB Dealership they said the Crankshaft Position Sensor failed. $ 350.00 later....No more problem.
Visitor, 2003 Mercedes-Benz E500, 98,000 mi
replased it twice
Only had the car for 3 months & the crankshaft position Sensor failure... today car wouldn't turn over due engine no start
Visitor, 2004 Mercedes-Benz E500, 90,000 mi
Had MB dealership replace sensor. Also battery drained, will have dealership replace second (non-MB) battery in two years.
Visitor, 2003 Mercedes-Benz E500, 60,000 mi
Would not start when warm, failed sensor
Visitor, 2003 Mercedes-Benz E500, 104,000 mi
It's exactly the same problem I have with my 2003 E500. Especially recently with very high temps in Dallas, the car cranks but won't start. After waiting for approx. 20 minutes it will start again. However, the last time it stalled in the middle lane of a busy road! Had to call for towing service but when the car was unloaded at home, it started again! I hope it makes it to the mechanic's shop and doesn't stall on the way there.