E320 Crank but won't start.
 

On three occasions my 2000 E320 SW would crank over but would not start. The first time this happened I called the local garage guy and after looking at the car he told me the spark plugs weren't firing and suggested that the electronic key lense may be scratched. I ordered a new key and when it arrived, I attempted to start the car with the new key. The didn't start but when I tried the old key it did start. I took the to the nearest Mercedes dealer and they couldn't fing anything wrong with the ignition system. About two week after that the same problem occurred. I let the car sit two days, tried it and it started. A couple of days ago the same problem occured again. I let the car sit for two days and it started. On the second and third occurences I inserted the key and let it sit for a couple of hours and the car started. Any ideas on what's wrong with the car?

E320 cranks but won't start
 

geored,

I had a similar problem with my 1998 E320. Dealer replaced my crank position sensor and problem was solved. Hope this helps.
:D