[EastCoast335i]

Originally Posted by Penn999

No, its not just on a cold start. I believe when he is saying a "cold" start he is meaning when the engine is completely cold. As in....has been able to sit for several hours and totally cool off. It is just more evident in the colder weather.

Well "so far" i've had two cold starts and no rough idle after pluggin the exhaust flapper valve back in....

I'm gonna keep testing my theory, but i think the exhaust flapper valve is something that our cars need for a smooth idle at startup...

[02themax]

Originally Posted by EastCoast335i

Well "so far" i've had two cold starts and no rough idle after pluggin the exhaust flapper valve back in....

I'm gonna keep testing my theory, but i think the exhaust flapper valve is something that our cars need for a smooth idle at startup...

Let us know how it goes. My car didn't do it every day at first but progressively got worse. Took it in they replaced the fuel pump and did software update. After 2 days it came back with a vengance thats when they finally replaced the injectors. Its just a matter of time with these cars...

[smk1028]

Originally Posted by 02themax

Let us know how it goes. My car didn't do it every day at first but progressively got worse. Took it in they replaced the fuel pump and did software update. After 2 days it came back with a vengance thats when they finally replaced the injectors. Its just a matter of time with these cars...

After reading/ worrying about this from previous threads mine finally went this week. It happend in quick succession-- the car was running fine until I started it Saturday AM, when it was a little bit rough. Each day upon the first start of the day it got progressively worse until yesterday (Wednesday-- 5 days after I started noticing it) when it would barely run-- flashing SES light, etc,. Shut it down, restarted it (it had heated up enough to run perfectly well by then) and drove directly to the dealership. The car is '08 E92 w/ 35k miles on it, and is unmodded (I do drive it like I stole it though), and AM temperatures have been pretty normal (high 40's, low 50's-- not freezing). They had the car overnight and here's what my service invoice says exactly and how they handled the issue per the PUMA:

"Injectors internally faulty and bleeding down.

Performed short test and found bank one misfire faults.

Followed test module and was promted to swap coils and plugs from bank to bank and let sit overnight to re-test. Swapped all parts as instructed and reassy micro housing. Let sit over night and car ran very poorly in AM. Removed plugs and found bank one fouled from fuel. Submitted TC case and was instructed to replace all inj and all plugs.
Replaced all inj and all plugs, registered all inj via ISID and then performed special drive cycle as requested per PUMA.

Items replaced include 6 spark plugs (high po), 6 injectors, and 6 decoupling elements."

I understand most of this jargon including the PUMA process, but some of this still escapes me (ISID, TC case, etc). After seeing this happen I'm wondering if this problem is considered "drivetrain" (i.e. my CPO 100k warranty would cover it if it happend again > 50k mi). The tech seemed to think this is a "one time" type of fix and that it "shouldn't" repeat itself.

Hope this helps others in the same situation... I took some cruddy iPhone video of it where you can see/hear how bad it was (figured I'd need it to convince the dealership there was actually a problem) but haven't a clue as to how to post that sort of thing on here.

[krypt0]

I have a rough idle on cold start also. Only happens after the car sits 8+hrs, and goes away 30sec after initial engine start.

No codes show up with BT scanner though.

My first guess was bad injector(s) but I'm waiting for it to get worse before it take the car in for warranty work.
I'm kinda scared they will update the S/W and then be greeted with the wonderful "lag". lol

[M_M]

my cars been running rough on cold starts for 6 months, but it would be back to normal after a min of drive, no code, no nothing.

[EastCoast335i]

Uh-Oh Longer then normal cranks....
Grrrr.. will this be HPFP number 2?!?!?!?

[RON1X]

there have a been a few threads about this, and it seems to be the newest software and how it primes the hpfp (possibly) prior to starting. I too was getting rough starts but after a minute of idling, no codes or anything and then the car ran completely fine.

Although, after I complained about it to my dealer (it took 2 times...) they replaced the hpfp and the car starts right up now. It is always something with the n54

[**335i**]

all depends on a weather is it cold or warm, here in LT we have at nights 0 and in a morning car starts really hard also it works louder on start up till it warms up

[tahoerdr]

I'm having the exact same symptoms as smk1028 describes (post #25). It's going into the dealer tomorrow so I'll update the results this week.

2008 335xi
40k miles
no mods
lead foot

It started happening 5 days ago and has gotten progressively worse, so rough that it nearly dies. It runs great after a few mins driving. "Service engine light" flashes.


UPDATE:

They swapped out all injectors and spark plugs. I don't understand why, but I swear there's more power and it also runs smooth on cold starts now.

[Drakos]

Same issue for me too. Rough startup and car drops below 500 RPM feeling like it is going to stall. This is after I complained about long cranks and the dealership updated the software. I got a CEL while driving and the car stuttered really bad. When I got home, I hooked up my BT and there were misfire codes on 4 cylinders. Have a service appointment this week.

[Sigma 3]

cold start a week after I bought it(labor day)? wich is not cold at all. it goes into limp mode 3 out of every 4 starts. Took it to the dealership today and their computers are down

[Penn999]

Originally Posted by Sigma 3

cold start a week after I bought it(labor day)? wich is not cold at all. it goes into limp mode 3 out of every 4 starts. Took it to the dealership today and their computers are down

Wow, thats some bullshit...I have run my car prettttty hard and have not yet hit limp mode. I think bmw owes you some $$$

[mave198]

I had a couple of rough idle cold starts recently when the temps have dropped overnight in the 40's.


NEVER happened when the temps were warmer. Got car in June.

[EastCoast335i]

UPDATE...

Well after plugging the exhaust flapper valve back in I have not had a rough idle since..
*knock on wood*

[gizmo335i]

Man, I'm having the same problem. But I'm getting thick exhaust fumes. They already replaced my spark plugs and an ignition coil and I still have the exact same problem. <<BTW, is an ignition coil the same thing as a coil pack? I'm ignorant on this stuff.

But I also am throwing a code. Interesting that you never did.

I just pray that it's not the HPFP going right now...I need to get mine back to the states for that damnit...I have no more warranty here!!

[gimmes name]

Hmm, I've had my car for ~3 winters now. First two did not show this, but this winter i'm seeing this problem as well. I do have the procede tune, but always figured it had something to do with the tune. I'm glad to hear non-tune cars are also seeing this.

BTW, I also have a plethora of other issues with my car. See my posts for more details. I wonder if you get my other symptoms as well?????

[dsswain]

I've also had 3 cold start issues in the last week. Once I notice it misfiring/studdering I shut it down immediately. Then restart it 2-3 seconds after, and it is perfect.

Do you guys really just let it run and work itself out instead of shutting it down? I find it very odd that it can mis-fire/idle soo badly, shut it down, start it and it runs fine.

If you shut it down and then start it does it still idle rough until warm? or is it fine like mine. Only mod is proceed.

[gizmo335i]

This would make me feel better if I wasn't throwing codes and SES...

BTW, this started when I had my JB3 in. I took it out and the exact same problem..so I don't think it has anything to do with a tune...

[mave198]

Just got my car back from the dealer and found spark plugs fuel fouled causing mis fire on cylinder 4-6.

They replaced all injectors, spark plugs, HPFP and LFP fuel line.

And a oil change.

Car runs great now.

[gizmo335i]

They replaced my spark plugs and one coil pack and when I picked it up, it still had the exact same problem. I took it back and it's been a week. They ordered new coil packs....they told me that Tuesday...they don't even know about the HPFP at this place...I have to pay for all of this too....if I was in the states....it would all be under warranty...damnit, this sux ass...

[Chupacabra]

Just bought my 335i. 2007 CPO with 30k miles. Already been in the shop 3x: once for the battery, then for hesitation on acceleration that was caused when it was in the shop for the battery, and now for rough idle. It idles fairly rough for a few seconds after a cold start, then it goes away. Dealer said it was not throwing a code so they cannot fix it under the CPO. So WTF?? They DO see/hear the problem, but say their hands are tied. No code=no fix! Man, I love this car: the looks, the drive, the engine, but I don't understand the loyalty to BMW when they make such a piss poor product compared to the Japanese. BMW really needs to step up their reliability, big time. I was hoping this would be my long term, classic toy for the next 5-7 years or longer, but its getting traded before the CPO expires. Maybe sooner than that.

[goztepe2002]

My car idles funky after a restart once the engine warms up. So cold (after the car being off overnight) starts are solid. Here is a video. Think im going to take it in for service.

2nd start is after i drove the car for about 10 miles.