2005 545i stalling at idle and accelerating from intersections

[tau1]

Hello everyone. I have a 2005 545i automatic with approx. 168,000 miles. A couple days ago the car began stalling when coming to a stop at idle, or other times when leaving a red light (i.e. taking foot off brake and pressing gas - car engine silently cuts out). Scanned using my Actron but no codes or SES light.

I've read other threads on related issues for various BMW models, and the issues generally seem to be cam shaft sensor, MAF, ICV or fuel pump. I took the car to the dealer and the SA suggested a potential transmission issue as well, but I had the trans rebuilt at 166,000 and it's been fine since.

Other background - I had VCG and Timing Covers replaced last month. original MAF, fuel pump and sensors. Also, the engine has had a deeper note lately, especially in the extreme cold weather, although performance has been fine.

Just wondering if there's any suggestions specific to the 545i so I know how to respond to the dealer this upcoming week.

Thank you very much.

[meangreen94z]

With no faults I would say an air leak. An air leak on an N62 sometimes will initially cause stalling/rough running with no faults or sometimes just misfire faults. Sometimes extended driving is required before mixture adaptation/ check sum faults set. I would smoke test for leaks.

[afstud]

i would start with replacing the fuel pump regardless since its the original also do the fuel pump relay which is located behind the glove box access panel, the left green relay on top of the regular fuses, My fuel pump relay wouldnt work when the car was cold (sitting over night cold) so i swapped a new relay in and its been firing up in super cold conditions great since and my slight idle jump went away as well as a result.

[tau1]

Thanks for the replies so far!

Since my last post this is more detail on the problem, the work done, and a few more things I noticed. @meangreen and @afstud i've taken your advice into account.

Main issue now is that the car for the last two weeks stalls at idle, but mostly when in stop-and-go situations like city traffic, or going from drive to reverse or vice-versa, or even just deaccelerating and turning into a parking space. But only when the engine is very warm and has been running for 20-30 min+. Constant stop-and-go seems to really aggravate the situation.

When the engine is colder it idles around 750 and that's ok. Once warmer it runs around 500 or even a little below and that's when it's more likely to stall. In traffic sometimes it suddenly dips well below 500 but then revs up to 700-1000 or so to save itself; othertimes it just stalls out. But after a stall it starts up fine. And other driving conditions, like highway, are problem-free. Acceleration and performance otherwise good.

Dealership looked at it and diagnosed the oil pressure switch (code D1140), which they replaced, and also noted "cats possibly clogged or aged" and "needs intermediate levers". I declined these last two and just did the oil pressure switch, but the problem continues. I've scanned the car several times lately on my own but no codes have registered.

I'm not sure about the cats as I've only had a couple codes for cat bank 2 ineffcienicy a few months ago but they never came back after clearing. And as far as the intermediate levers go I do hear more of an engine knocking lately but wasn't sure if maybe that was just because of the extreme cold here in the N.E.

Anyway, I asked the dealer if they also checked for air leaks or fuel issues and they said "yes" but just not sure. They quoted me $5k for the cats and another $5k for the levers and I want to know if i'm just being pushed to buy a new car from them vs. fix the real issue. I plan to trade the car in sometime this year anyway, so not looking to do major work at this point. And no way i'd pay those prices anyway!!

Here are some possibly relevant repair history details:

- Oil pressure switch at 168,000 (second time - dealer warranty)
- Valve cover gaskets and upper timing cover gaskets at 167,000 (second time - dealer warranty)
- Thermostat at 167,000 (second time - dealer warranty)
- Trans rebuild at 166,000 (ind. shop)
- New battery and alternator at 163,000 (ind. shop)
- Thermostat at 135,000 (dealer)
- Vacuum pump at 117,000 (dealer)
- Oil pressure switch at 117,000 (dealer)
- Valve cover gaskets and upper timing cover gaskets at 117,000 (dealer)
- Ignition coils at 110,000 (dealer)
- Sparks at 95,000 (dealer CPO warranty)

I have original fuel pump, MAF, ICV, CPS, O2s and Cats.

Thanks