P0015 and stalling
 

So our 08 X3 with only 110k miles runs great 99% of the time, but once in a while it will stall when coming to a stop. Otherwise plenty of power and good gas mileage.

I've had a P0015 code, so I replaced the cam position sensors and VANOS solenoids (very simple job). Cleared the codes, drove, still stalls, and the code came back.

Reluctantly took it to a local independent BMW shop hoping they had better diagnostics. They said "you have a P0015 code and we would like to put in new VANOS solenoids for $700".

So that was a big waste of time. Any suggestions? Oil is always clean and th car runs like a champ otherwise. Some might be inclined to suggest gas filter, etc, for the stalling but that would not explain the code.

They didn't scan it with a BMW specific scanner, like an Autologic, to get a more specific diagnostic code?

I not sure what they used for diagnostics, but I thought it would be more sophisticated than my $50 scanner. I was disappointed that the mechanic had no more idea what was going on than I did.

He then told me that his scanner said that I needed a transfer case oil change. His face reddened when I told him his shop had done one 2000 miles ago.

That is disappointing. On a number of levels. Either they didn't reset the computer so it reflected their previous transfer case oil change, or they just rail that line off to everyone who comes in with a 4x4 BMW.

I'd take it to another shop at this point though. Someone with a more in depth diagnostic setup. P0015 could be vanos, cam sensor, etc. I'm not as familiar with the N series of engines as we have an M54 powered mtech x3 but a better scan would probably help point you in a better direction.

Let me catch you up on this because it might help someone else.

I took it to a better shop about an hour away and we found two problems.

1. The VANOS timing sprockets were worn. In replacing those we also replaced the eccentric shaft sensor, and the timing sprocket, and re-timed the cams.

2. The CVV was not working intermittently. It's integral with the valve cover (N52N) so we replaced it with what must be the worlds most expensive valve cover. I don't think even Ferrari charges this kind of money.

Anyway we put 500 miles on it in less than 18 hours after leaving shop and so far, so good. No stalls, no flakey idle, no SES, no P0015.

I've owned cars for 45 years and do most work myself. This event was the largest single repair bill I've ever paid. Informed wife she will be driving this car now for at least another five years.

Glad you got it sorted. Yes, the N series of engines has some expensive design/engineering choices associated with it, which is why the wife and I specifically looked for a last year M54 X3 w/ mtech package. Less power yes, but way cheaper to maintain.

Thanks again for updating.