Continuous cranking, no start

[FISH22]

First time I have seen this happen with my car. Ran into a store, car was off for just a few minutes. Came back out, hit the start button, and it just cranked. I let it go for what felt like a lifetime, but it probably cranked for about 5 seconds. I immediately hit the button to stop it. Sat there puzzled, then tried again. Fired right up. Was very strange. Has never happened before, so was this a fluke thing? As the car cranked, it sounded healthy and strong as usual, just wouldn't fire up.

Car is an '11 E90 M3, 6MT, bone stock, with just over 36k miles. I have only owned it for the last 4K miles (about a year), and it's been great since.

[msan]

Originally Posted by FISH22

First time I have seen this happen with my car. Ran into a store, car was off for just a few minutes. Came back out, hit the start button, and it just cranked. I let it go for what felt like a lifetime, but it probably cranked for about 5 seconds. I immediately hit the button to stop it. Sat there puzzled, then tried again. Fired right up. Was very strange. Has never happened before, so was this a fluke thing? As the car cranked, it sounded healthy and strong as usual, just wouldn't fire up.

Car is an '11 E90 M3, 6MT, bone stock, with just over 36k miles. I have only owned it for the last 4K miles (about a year), and it's been great since.

Well in the Mercedes world this would be a symptom (strong crank but no start) of a bad crankshaft position sensor. It would throw a code if this happened. Might be good to get a check to see if you have any codes to be read to help you locate the problem.

[Facsombh]

http://www.m3post.com/forums/showthread.php?t=996069