[jeffzoom]

I have 47k miles on my car, it's bone stock (M4 LCA not withstanding) and occasionally on cold starts it'll bog hard enough to shake the car.

This morning I went out to move it and it actually stalled. Attempted to restart, it stalled again. Third try I gave it a little gas and it ran.

This only seems to happen on cold starts, if it's warm it starts fine. It also doesn't happen all the time, but has a much better chance if I drive my other car for a day or two.

I also have the occasional 1st gear slow speed stutter thing.

Has anyone had this happen to them on a 6MT that's stock? I searched but all the previous incidents seem to have a JB4 or an intake or something.

I have an appointment with the dealer on the 2nd, any ideas on how to explain this to them?

[overcoil]

Carbon deposites
Weak Battery - only when cold ?

Assume it's not bad gas.
Just tell dealer what you write here. Guess they'll check fuel rail pressure, air filter and housing for debris, and probably ask you to leave car overnight and attach diagnostics on the morning start to try to duplicate.

[jeffzoom]

I'm trying to catch the incidents on video, hopefully I'll have a good one by the time I have to drop the car off.

I should clarify on "cold start", I'm in Florida so by cold I mean "Haven't driven in a while".

[dtcoff]

Mine has has a problem with cold starts since about 6 months old. Has been back to the dealer many times and BMW have created a PUMA for it. Lots of software updates and injector cleaning that resolved it for the next couple of weeks before returning. It does it every cold start now rather than just most times. It went in again last month and they changed the crankcase sensor, but still not fixed. Car is completely stock.
https://www.youtube.com/watch?v=o5c7Suz7voA

[jeffzoom]

Originally Posted by dtcoff

Mine has has a problem with cold starts since about 6 months old. Has been back to the dealer many times and BMW have created a PUMA for it. Lots of software updates and injector cleaning that resolved it for the next couple of weeks before returning. It does it every cold start now rather than just most times. It went in again last month and they changed the crankcase sensor, but still not fixed. Car is completely stock.
https://www.youtube.com/watch?v=o5c7Suz7voA

That's it! That's it exactly!

It did this twice today, but with 6MT, so didn't even need to leave neutral.

It only recently started getting worse, usually the bog down isn't too much.

I don't think it's a HPFP issue, the car does fine under...let's call it "Spirited Off-Road Commuting".

The only thing I can think of is that I don't remember hearing the fuel pump prime when I opened the door this morning. Normally I hear it after 24 hours or so of not driving.

[amw896]

plugs brother, plugs.

[pz619]

I'm curious to know when our cars need carbon cleaning. That could be an issue based on your mileage so just throwing that out there.

[Taunto]

Hello
Here in Alberta We see this issue at least once a day in the winter months.
More so this year than most on the N55 and S55 engines.
We have done Plugs, coils, programming, cleaning, MAF etc, and all this temporarily fixes the issue for a short time. It is how ever interesting to see it happening in Florida as well in much warmer climates..

We at the dealer have sent multiple requests to BMW about this issue and have been told that they are currently working on a software update to hopefully resolve this issue.
For me personally I have noticed that running regular fuel has helped this issue. And also have heard from customers when they use premium fuel from a different fuel station it seems to help/go away as well.
My theory for my local area and probally even canada.. is it has something to do with how the chemicals are mixed in the premium grade fuels...but this is just an assumption with no proof/documentation to back it.

Im interested in hearing what your dealer finds out and if the issue is resolved.
Keep me posted please

[123Britt]

IS YOUR FRIEND - I just picked one up knowing that all kinds of things start to occur post 50k miles on a BMW .

[XutvJet]

Originally Posted by Taunto

Hello
Here in Alberta We see this issue at least once a day in the winter months.
More so this year than most on the N55 and S55 engines.
We have done Plugs, coils, programming, cleaning, MAF etc, and all this temporarily fixes the issue for a short time. It is how ever interesting to see it happening in Florida as well in much warmer climates..

We at the dealer have sent multiple requests to BMW about this issue and have been told that they are currently working on a software update to hopefully resolve this issue.
For me personally I have noticed that running regular fuel has helped this issue. And also have heard from customers when they use premium fuel from a different fuel station it seems to help/go away as well.
My theory for my local area and probally even canada.. is it has something to do with how the chemicals are mixed in the premium grade fuels...but this is just an assumption with no proof/documentation to back it.

Im interested in hearing what your dealer finds out and if the issue is resolved.
Keep me posted please

This is interesting because back in early November during the first real cold day of the year (upper 30s) and right after winter gas made it's way into Kansas City, my 2016 M235 (first winter with the car) threw a CEL for a Bank 1 lean condition within the first 3 minutes of driving that day. Based on research, that CEL is often thrown for a flaky 02 sensor. The car ran fine. I took it in that same day and the dealer had 3 other BMWs come in the same day for the same issue. Apparently a new SIB was issued because of the issue in some cars through the US. They updated the DME and the issue never reappeared. According to the tech, some cold start sensors in newer BMWs don't deal well with certain US winter fuel additive packages.

I would suggest to anyone experiencing weird cold start behavior to first switch filling stations and see if they issue continues. You may also want to consider trying to find 91 octane vs 93 if you live in an area that experiences winter. The reason being the higher the octane, the higher the fuel's resistance to pre-detonate and to a minor extent, ignite under cold ambient and engine conditions. It could be possible that BMW's tuning is such that there is a very fine line between cold start efficiency to warm up the motor/cat and just a very poor cold start. Being that it's cold outside, 93 and higher octane really isn't necessary assuming you have a stock car or the more standard engine modifications.

It could also be plugs or coil packs

[jeffzoom]

My current theory is something related to a heated sensor. MAF, O2, something that's temperature dependent.

I did recently have my charge pipe replaced under warranty, but it doesn't have any boost leak issues (that I can feel anyways) and fuel economy appears mostly normal.

Even if I only run the car for 5 minutes, the next start is completely smooth.

It doesn't really seem to be effected by the gas station I use, but normally it gets Sonoco 93 from a station across from a Ford dealer. They also sell race gas, wonder if that will fix the issue

[jeffzoom]

Car came back from the dealer.

Software flash and it's back to normal. Didn't fix the slow speed stutter thing though.

Car feels more linear, turbo lag reduced.

It also knocked out all my coding, and I have to await updated data because my old coding software doesn't work anymore. At least it's fixed though.

[DaveM235i]

I had the same issues - cold start only. It would start then dip to below 400rpm then jump quickly past 2000rpm. I recorded it and scheduled it on at my BMW dealership.

On the worksheet in front of me it states "Check for Puma measures relating to complaint Puma No 60346047-02 to carry out programming and encoding. Carry out re-programming as per Puma measure and cold start test vehicle - All ok."

They said it was a software issue, reprogrammed it and i got it back last night. I had the issue every single morning with a cold start - other starts throughout the day were fine.


I fired it up this morning and it was a perfect start. Let's see what tomorrow brings.

[alexvegas65b40]

Originally Posted by jeffzoom

I have 47k miles on my car, it's bone stock (M4 LCA not withstanding) and occasionally on cold starts it'll bog hard enough to shake the car.

This morning I went out to move it and it actually stalled. Attempted to restart, it stalled again. Third try I gave it a little gas and it ran.

This only seems to happen on cold starts, if it's warm it starts fine. It also doesn't happen all the time, but has a much better chance if I drive my other car for a day or two.

I also have the occasional 1st gear slow speed stutter thing.

Has anyone had this happen to them on a 6MT that's stock? I searched but all the previous incidents seem to have a JB4 or an intake or something.

I have an appointment with the dealer on the 2nd, any ideas on how to explain this to them?

Something similar happens to my 2011 e90 m3 on "cold starts" it will almost stall completely and has problems to idle correctly after, when it starts to warm up its gone. I quoted cold starts because where i live the weather even in the winter is not cold. I recently replaced my battery and spark plugs and this has not made an impact on the problem, it comes and goes when it wants to basically. Im thinking it might be the injectors but i have not looked into them.