Mercedes w210 e280 starts but cuts out?

[mrmarcus]

1999 merc w210 e280 v6 petrol. Drove about 300miles home for Xmas. Car running perfect. Next day drove car to local shops, came back after few mins and car won't start. Tried starting every few mins, cranking strong just not firing up, then starts after about 20 min. Runs smooth and perfect. Let it idle for a bit, seems ok and as about to set off, cuts out. Will not restart. Called family and towed back to house.

Since then i have established that from cold, the Engine starts no problem but after about 15 or 20 mins idle the engine cuts out. If I try to restart it, just cranks over and won't fire up. I've taken a spark plug out to see if I have spark on cranking when it cuts out and I don't. (also checked When engine cold, and I do have spark and engine runs minus 1 cylinder!.) If I wait about 20 or so minutes after it cuts out, then it will start again no problem but after it warms up to normal temp again it cuts out and will not start again as before unless I wait to cool again. The temp gauge does not rise beyond where it normally sits about mid way (82 ish deg c). Everything under bonnit seems ok, all fluids ok, radiator hoses etc.

Is some sensor telling the engine to shut down and won't let it restart for some reason? Can anyone Advise what may be going on? Any way to DIY fix it or is garage only option?

Thanks any advise appreciated.
Mrm

[angusc43]

Sound like the crank sensor - or at least I have had what sounds like that exact problem on both my C43's and on my W211 E500.

The part is pretty cheap and it takes half an hour's labour or something.

[r129sl]

I second the crankshaft position sensor. Dealer will have one in stock and will change it in half an hour or less.

[mrmarcus]

I replaced the crank position sensor and the car runs perfect now! Cost about £34 for the new sensor. Located on the back of the engine on passenger side. Access very tight to get at it. Thanks for advice guys