[RedRocketM2]

My car is doing a strange thing on cold start up. It starts and within seconds the revs drop to almost the point of stalling and then it revs to well over 2000 rpm then settles down to normal cold start idle rpm. The car seems to be running normally and there are no fault codes and it does not seem to do this when the engine is warm.
The car is due for its second servicing in the next month or two but I am going to bring it in to have this looked at sooner rather then later.
Just wondered if anyone else has experienced this issue and what the cause was.

[configt]

I have seen others complain about this on the forums recently. The common thread seemed to be people in colder climates. Are you running 100% stock?

[jb606]

Mine does the same thing randomly and it doesn't seem to matter what the outside air temp is. I'm going to bring it up the next time I take the car in for service.

I started a thread a while back, http://www.2addicts.com/forums/showthread.php?t=1128357.

[RedRocketM2]

My car is in a climate controlled garage and it began over the last month so cold weather has not been a factor.

Thanks I will check out your thread

[Wheelwright]

I had this problem couple of months back when I was on Shell fuel. Probably bad fuel batch. The problem didn't return since.

[RedRocketM2]

Thats interesting I usually use Shell fuel. Maybe I will try using a different brand of fuel for a few tanks and see what happens

[Cyberdemon]

This is usually the sign of some fuel delivery issue. Whether it's bad fuel, a pump issue etc, should get it checked out.

Did it just start since your last tank of gas - and does it happen on every cold start? If so you can just try to run the car hard for a bit to burn up some gas and then refill the tank to see if anything changes.

[DanG]

Mine actually has stalled several times after a cold start. It is going in on July 7th.

It is funny because it always starts and runs fine the second time.

[jb606]

Originally Posted by DanG

Mine actually has stalled several times after a cold start. It is going in on July 7th.

It is funny because it always starts and runs fine the second time.

Without a bunch of logs and fuel pressure readings there's no real way to tell what the problem is but it sounds like the fuel system didn't get a good prime.

[mike@x-ph.com]

Sounds like a fuel delivery problem that being said BMW dont have the best idle on cold start.
My car has been doing that for the last 2 years. Had 3 fuel pumps changed and everything checked. Cant find the cause of the issue.

[DanG]

My car is in the fuel pump recall. I'm hoping to just get a new fuel pump instead of the forever hold.

[Jeff@TopGearSolutions]

It sounded like a fuel pump issue so this makes sense.

[RedRocketM2]

Thanks guys I will let you know what the dealership says
It only seems to do it every few cold starts not every time.

[DanG]

Car went to the dealer today. They want it until at least Friday to try several cold starts.

I'll report back on what corrective action they took if any.

Off topic, I'm now driving a 328i loaner. Let's just say that it is not my favorite car.

[overcoil]

The symptom described is what direct injection carbon deposit issues are known to create - but that's at 40K miles or more.

[Flipwit]

Originally Posted by ScottSinger

The symptom described is what direct injection carbon deposit issues are known to create - but that's at 40K miles or more.

rumor has it that the new programming under the F2X models using the N55 platform have significantly reduced carbon buildup on the valves to the extent that most manufacturers of oil catch cans aren't developing models for the F2X series. I don't necessarily believe that they've fixed the issue without some sort of solvent (gas, water, etc.) being ran over the valves or some sort of valve timing change allowing more airflow over the back of the valve or a change in pcv design...

That being said, fuel delivery or fuel quality seem to be the culprits here as carbon buildup typically causes rough idles and power loss, not necessary bouncing RPMs on cold starts.

Purely anecdotal but I only put Chevron in my car, to the point of aggravating my girlfriend by driving more miles to find a Chevron station over a Shell station and haven't had those problems yet. Again, anecdotal, but worth considering.

[DanG]

Just got my car back from the dealer. They replaced the fuel pump and reprogrammed the car.

Car had a flexray fault stored.

[DanG]

Update: two days later and no more cold start stumbling or dying.

Sounds like I'm all fixed.

[RedRocketM2]

I took my car in finally this week and I could not help but laugh at my dealers explanation of the problem.

My service advisor told me the starting issue was caused by contaminated oil. He went on to explain there were no registered fault codes and there are no recalls on the car.

I truly don't believe this is the issue and I am waiting to how soon it reappears

I have never heard of such a thing. But hey if it is bad oil then I guess I have learned something new LOL....

I will keep you posted.

[Killramos]

If i start my car cold and put it straight in reverse it nearly stalls every time, though has never actually stalled. Repeatable.

If i wait for the idle to die down to below 1000 rpm then 0 problems.

Makes me feel stupid when people ask me why i am waiting to move in a parking lot.

[aerostar]

That's pretty normal for a car to not want to start moving right after you start the car...

My WRX used to do the same. The computer is telling the engine to keep the idle RPM a little higher as the engine's cold and you're killing its mojo by connecting the transmission lowering the RPM to choke it out

[mbrito31]

The same thing just happened to me this morning for the first time. Awkward start and at idle was almost at a stall. Put it in reverse to move it and suddenly it was at a normal idle? Is this something that I should be concerned about?