Idle/Staling Issue, Dealer Can't Fix

[ReD-DaWg-OnE]

I have had my 09 E90 6MT for about 1.5 years, I purchased it with 39k miles and it currently has 65k. I have not done any modifications to it, but I do drive it moderate to hard.

The car has a sporadic idle, a lot of the time. It will normally fluctuate 50-100 RPM at idle, but doesn't seam to have any pattern to it because other times the idle is just fine. Other times the idle is more sporadic moving a couple hundred RPM and then the engine dies. This only happens at idle and has never died on me while driving, it used to occur right after fueling most frequently.

The dealer (BMW of Bakersfield) has had the car for the same issue approximately 5 times and it keeps having the same issues.

They have replaced the idle actuator 3 times, reprogramed the DME, replaced the DME and most recently replaced the fuel pump. They said they have been working with BMW NA on this issue, but told me on Friday they are going to have to start back at square one and go over everything again.

I've been really patient with them but have cumulatively been without my car for 2-3 months and have thought about calling BMW NA myself.

Do you guys have any ideas on what could be the issue, or where I should go from here?

I was thinking of trading it in on a new M3, do you think BMW NA would be willing to work with me on that?


List of issues the car has had other then stated above.

1. New AC evap
2. Taillight just started failing
3. It looks like the amp is failing as sporadically there is no audio from radio, phone or AUX.

Thank!

[BrewRifle]

Have you tried going to a different gas station in order to rule out fuel?

[kscarrol]

I had an erratic idle with occasional stalling, particularly after filling up. Dealer replaced the fuel tank breather valve and that solved the issue. If this has not been replaced as part of the fuel pump work they did, have them try replacing it.

I was able capture the rough idle on video and showed it to the senior service tech at my dealer. His first thought was the idle control valve but another member had been down this path and he pointed me in the right direction.

Edit: See post 20 in this thread for the video of my idle issue...

http://www.m3post.com/forums/showthr...2Brough%2Bidle

[fastmike]

Definitely sounds like the same symptom, my car does the same thing.

Hopefully next time I'll get it replaced next time I take my car in.

Originally Posted by kscarrol

I had an erratic idle with occasional stalling, particularly after filling up. Dealer replaced the fuel tank breather valve and that solved the issue. If this has not been replaced as part of the fuel pump work they did, have them try replacing it.

I was able capture the rough idle on video and showed it to the senior service tech at my dealer. His first thought was the idle control valve but another member had been down this path and he pointed me in the right direction.

Edit: See post 20 in this thread for the video of my idle issue...

http://www.m3post.com/forums/showthr...2Brough%2Bidle

[kscarrol]

Yes, seems somewhat common. In fact my dealer had another M3 with this issue and they were perplexed as to the cause until I suggested the fuel tank breather valve. Member gpitts (see thread I linked to earlier) was the one who pointed me in the right direction as he had brought his car in several times looking for the fix. In hindsight I should have let them replace the idle control valve so that I had a new one as roll off of my factory warranty!

[ReD-DaWg-OnE]

I have an appointment on Monday, I will tell the SA on Monday hopefully we can get it resolved.

Thanks for pointing me in the right direction!

[squartus]

I have had mine die when I was filling it up with gas with the engine running, just figured it was some safety feature but maybe its this ticky breather. Never had it die any other time though.

[darkbmw]

Could a dirty mass air flow sensor cause it

[s85e90]

Originally Posted by darkbmw

Could a dirty mass air flow sensor cause it

there is none on the m3.

OP if stalling after fueling and seeing the other poster here mention it, I would also press them about the tank vent. There may be an issue with it (should really be simple).

[BPMSport]

Originally Posted by s85e90

there is none on the m3.

OP if stalling after fueling and seeing the other poster here mention it, I would also press them about the tank vent. There may be an issue with it (should really be simple).

This isn't entirely accurate. There is an air mass measurement on the secondary air circuit.

OP: are there any fault codes? I would replace the low pressure fuel sensor as well.

[s85e90]

Originally Posted by Mike Benvo

This isn't entirely accurate. There is an air mass measurement on the secondary air circuit.

OP: are there any fault codes? I would replace the low pressure fuel sensor as well.

That's not a convetional MAF meter as usually found in the intake tract. For all intents and purposes this car is speed density.

[BPMSport]

Originally Posted by s85e90

That's not a convetional MAF meter as usually found in the intake tract. For all intents and purposes this car is speed density.

You're correct that the secondary air circuit doesn't have a large MAF, but it meters air nonetheless.

[5soko]

V10 M5's have the same issue for years, and no1 has seemed to find the cure..

[s85e90]

For what it's worth sometimes my e46 and e90 have done this. Cold start, then will have a slightly lopy idle. Never had any issue though.

[ReD-DaWg-OnE]

Still waiting to here back from the SA, she told me they are running everything threw the PUMA case.

Has anyone filed a complaint with the NHTSA before?

[JHFW89225]

I have this problem as well, glad that you ask. I believe it's the fuel breather valve, I am pretty sure that's the fix as another member pointed out. Been with BMW back and forth for a year figuring things out and it's not the idle valve or injector or spark plug or anything.

In the mean time, if u keep ur foot on it and raise the revs a bit during the idle after filling up, it won't stall! After a couple km of driving and repeating and it goes away until the next fill up. Wierd!

[ReD-DaWg-OnE]

Spoke with the SA today, she said BMW wanted her to replace the fuel pressure sensor, as well as the fuel line going from the fuel tank all the way to the engine.

I should have the car back tomorrow and know if it is fixed.

[ReD-DaWg-OnE]

Originally Posted by JHFW89225

I have this problem as well, glad that you ask. I believe it's the fuel breather valve, I am pretty sure that's the fix as another member pointed out. Been with BMW back and forth for a year figuring things out and it's not the idle valve or injector or spark plug or anything.

In the mean time, if u keep ur foot on it and raise the revs a bit during the idle after filling up, it won't stall! After a couple km of driving and repeating and it goes away until the next fill up. Wierd!

That is very similar to what is happening, it appears that as time went on it progressively got worse.

Does anyone know when a PUMA case is opened if they actually speak with someone from BMW or is it some kind of website where they put in the facts and they tell them where to go?

[MTM]

OP: Have you been able to notice whether or not it happens with a mostly full tank, half, or mostly empty? If it is the fuel vent then I would wager the problem happens more often with a full tank (i.e a stuck / clogged breather + higher pressure in the tank = vapor lock).

[JHFW89225]

Originally Posted by MTM

OP: Have you been able to notice whether or not it happens with a mostly full tank, half, or mostly empty? If it is the fuel vent then I would wager the problem happens more often with a full tank (i.e a stuck / clogged breather + higher pressure in the tank = vapor lock).

It used to happen so rarely that I didn't keep track because I figure it was one of those little gremlins. And since it didnt directly affect the driving and i let BMW figure it out, I just let it slide at the time.

Now it does it not matter how full the tank is, as long as I add gas the symptom will appear, if not then it never does.

Anyhow, thanks to gpitts's case and my case with bmw for more than a year I am pretty convinced about the solution is the gas vent valve. I've had the idle value replace and it didnt do anything.

Now my car is out of warranty but BMW Canada did place my car under a good will program. I'll get around to fixing it when I have time

[fastmike]

I mentioned to my mechanic about the fuel tank purge, he said plausible but said if they get stuck they'll usually throw a code. But Noone has seen a code thrown with this stalling right? I haven't seen any codes on my car.

[kscarrol]

Nope, no codes on my end. But replacing the fuel tank breather/vent valve resolved my issue...