Most of the actors in Ghostbusters got their start in Chicago.

If issue with ignition switch, you won't be able to crank.

Yep, true too... hmmmm. How bout this... maybe a gear position switch or something? Not sure what the technical name for that is... but now that I think about it, that would be a no crank as well.

Cranking with no start can only be a few things... spark, fuel, and air is all you need to fire up. So something is preventing one of those things during this problem.

A sure fire way to diagnose it would be to stick it on an autologic or other BMW specific computer that can read each sensor's status. Only problem with this is that it has to be malfunctioning at the time... and since this is intermittent that could be hard.

What about a crank positioning sensor? I've had crank with no start on 3 series cars before with a bad CPS... sound plausible?

Drive her to a dealer and get her scanned. My X3 does it to me the same exact symptom, and left no error message at all. However, when I went to this indy, a very well equipped indy, they scanned my X and pin pointed that exact sensor within 10 minutes. Basically he's sending signal to each sensor to test them running, and the bad one will just keep sending back bad signals.

My X3 is N52 by the way. Good Luck!

My 2000 X5 4.4 doesn´t have exactly the same symptoms but some times , like once on every two or three months it just dies while cruising. I am able to restart at first crank and no lights are on. I wonder why does it shut off like this, it can be dangerous!

Thanks! She is getting scanned at bmw as we speak, but of course it was running perfect when I pulled in. Pretty sure the tech thinks I'm making up the stalling issue. They don't seem to get how dangerous it is!

-few years back this happened
 

as I recall someone in california reported a similar issue going around a bend at 30 mph or so in around 2009 or 2010. If that OP is still around or someone recalls, I believe they resolved the issue and got to the root of the problem. Same circumstances and mystery. I know this probably wasn't of any help but maybe it will jog someone's memory better than mine... In the meantime, I'll see if I can put search to good use...:dunno::dunno:

Thanks!

UPDATE after 7 hours at the dealership, we ended up changing out the IVM module (Integrated Supply Module) and switching around the vanos solenoids. Since this has been inconsistently happening I'm hoping this is a fix, but time will tell. The great thing about this dealership is that if the IVM is not the fix they will put my old one back in, credit the cost and try something else so I'm not dumping money into the issue without a solution. :thumbup:

That is a very cool dealership... wish we had one like that.

Good luck, hope you got it. Keep us updated.

We need the name of that dealership. Meanwhile, you can tell them, once you earn my business, you will earn much more (Xoutposters)! ;)