BMW cutting off while driving... - BMW Forum

Cheryl G · 07-26-2011, 08:23 AM

After two times in the shop, no one can find why my 330i is randomly not starting......it always starts on a cold start but randomly doesn't start on a hot start. It always turns over, just doesn't start. After some time passes, (from 5 minutes to 1 1/2 hours) it will start (suppose after temp on motor drops). This happens so randomly, it cannot be duplicated. So, I was driving it about two weeks ago and it cut off while driving full speed (approximately 55 mph). Pulled off road and after about 15 minutes it cranked and I drove it home and it has been parked since. Can someone please help me determine what the problem might be? No codes are being displayed. Thanks.

m1dn1t3 · 09-07-2011, 01:00 PM

Hi Cheryl ..to me that sounds like ur crank positioning sensor... German car r known for that, I have a buddy of mine that had that same problem he use to drive around with a gallon of water so when it shut off he would dump some water over the sensor and it would cool it of and crank right over... Hope u found ur answer. Good luck.

Jack Dabsy · 09-07-2011, 01:40 PM

Quote:

Originally Posted by m1dn1t3

Hi Cheryl ..to me that sounds like ur crank positioning sensor... German car r known for that, I have a buddy of mine that had that same problem he use to drive around with a gallon of water so when it shut off he would dump some water over the sensor and it would cool it of and crank right over... Hope u found ur answer. Good luck.

It's an idea as my M52 was parked uphill for some weeks and refused to start at all... I put it down to the oil not reaching the cam sensor to clean it/cool it...

Cheryl G · 09-07-2011, 01:58 PM

Quote:

Originally Posted by m1dn1t3

Hi Cheryl ..to me that sounds like ur crank positioning sensor... German car r known for that, I have a buddy of mine that had that same problem he use to drive around with a gallon of water so when it shut off he would dump some water over the sensor and it would cool it of and crank right over... Hope u found ur answer. Good luck.

Thanks for your reply-however, I had one of the sensors replaced recently (either cam shaft or crank positioning sensor). Also, just replaced fuel pump on a whim that it could be that. It certainly seems to be fuel related. I have not driven the car since July 12, 2011, when it cut off going down the road. I have occasionally gone out to start it, though, and sometimes it cranks and sometimes it doesn't. No rhyme nor reason. Today, someone read the codes and it showed low compression on fuel injectors (or something like that). The car will fire with starter fluid (ether) but will not continue to run, like fuel is being shut off. Still, I'm dumb founded with all this, sometimes it will, sometimes it won't stuff. Anymore options I should try?

Jack Dabsy · 09-07-2011, 02:04 PM

Has to be an air-lock in the fuel-line... Purge the fuel rail using the attached valve... Maybe install a non-return fuel valve in the fuel-line before the throttle-body...
HTH

Cheryl G · 09-07-2011, 02:14 PM

thanks, will check into that

Jack Dabsy · 09-07-2011, 02:19 PM

No problem... Keep us informed !

Cheryl G · 09-08-2011, 11:33 AM

Mechanic checked codes yesterday and said there were a bunch listed, however, the car continues to start for him. Not one time since he has had it has it not started!! What to do, what to do??? If he can't get it to not start, then how will he find what is wrong with it?

Jack Dabsy · 09-08-2011, 01:16 PM

WHat did they attach to the car while this was happening? Just a scanner, or something extra?

Cheryl G · 09-12-2011, 07:33 PM

not sure, but will try to find out.

thedrakester09 · 09-18-2011, 04:00 PM

Quote:

Originally Posted by Cheryl G

Thanks for your reply-however, I had one of the sensors replaced recently (either cam shaft or crank positioning sensor). Also, just replaced fuel pump on a whim that it could be that. It certainly seems to be fuel related. I have not driven the car since July 12, 2011, when it cut off going down the road. I have occasionally gone out to start it, though, and sometimes it cranks and sometimes it doesn't. No rhyme nor reason. Today, someone read the codes and it showed low compression on fuel injectors (or something like that). The car will fire with starter fluid (ether) but will not continue to run, like fuel is being shut off. Still, I'm dumb founded with all this, sometimes it will, sometimes it won't stuff. Anymore options I should try?

i had the exact same problem but it was for 2004 E60 with an M54
it turned out to be the fuel pump relay. you can try that it's cheaper than just replacing random sensors.
and BTW it's not likely the crank or cam sensors because they almost always store a fault if they've gone bad
hope it helps

Cheryl G · 09-18-2011, 08:25 PM

thanks the drakester09. i should have mentioned in an earlier post that the first thing we tried was switching the relay-swapped horn relay with fuel pump relay-no change. Thanks for the info, though.

Jack Dabsy · 09-19-2011, 02:46 PM

Doh!!

Cheryl G · 09-21-2011, 03:17 PM

Still no luck......went to pick up car today, mechanic said it has started every time. He is going to drive it this afternoon for about 50-60 miles to see how it does. I hope I get this crazy car back tomorrow; I sure do miss driving it.

Cheryl G · 09-23-2011, 02:50 PM

Ok, back from the mechanic and guess what???? Car will NOT start!! urg!! Could this be ignition? Anyone....I appreciate your input. Thanks.