tonyb635

GOOD UPDATE:
Today my CE illuminated after work and of course the stumbling issue has not gone yet... When I got home I pulled out Mr. IMPA and checked for the codes. I saw the typical chatter in there but there was one strange thing. Under the DME/DDE it showed number items 0447, 0067, 0068, 5300, 62B6,7404,0444, B700, 62B1,

Now when I cleared them and then re-ran it, it pulled up code 29D2. After doing a little research it led me to this posting I found from another person that is posted below. It looks like the issue is an injector or perhaps plug and or coil. Kinda the direction we were all going. This weekend I'll grab some plugs and I think what I'll do is start the car let it idle for a few minutes then turn it off and pull them. I'm hoping that if it's an injector I'll see a fuel soaked spark plug. Otherwise, I'll change them and see if I can figure out anymore from there. When I looked in my shop manuals last night the code 29D2 says that it's a misfire in cylinder 6. Now I feel like I'm getting somewhere...

From Post:

OK...I did do some research..I found 2 bulletins one for the rough start when the car is cold and the other one is the 13-05-08...here are both anyway:

13 04 09 Cold Start rough running with misfire faults

SUBJECT
N54 - Cold Start Rough Running with Misfire Faults


MODEL
E82, E88, E90, E92, E93, E60, E61 with N54 engine


SITUATION
The customer may complain that during the cold start in the morning, the engine runs very roughly and the Service Engine Soon lamp is illuminated.

Various misfire fault codes (e.g., 29CC, 29D2, 29D1, 29D0, 29C0, 29CF) may be stored in the DME control module.

The engine rough running complaint can be reproduced on a cold start in the workshop. During the course of diagnosis, the spark plugs, removed from the misfiring cylinders after the problem was reproduced, are found to be soaked ("wet") with fuel, while the injector tips are covered with a layer of carbon deposit.

CAUSE
Possible cause: high pressure injector failure (leakage or incorrect spraying pattern), due to internal wear or unfavorable stack of tolerances

CORRECTION
In case of a reproducible "cold start" rough engine running with corresponding misfire faults, replace the high pressure injector of the affected cylinder, using the improved part (P/N 13 53 7 585 261). Follow TIS Repair Instruction RA 13 53 310 for injector removal and installation. If the spark plug from the misfiring cylinder shows wetness (fuel soaking) after cold start removal, then it should be replaced as well.

After an injector replacement, perform the individual injector calibration (adjustment) with the DME control module, as per SI B12 26 08.

IMPORTANT:

If during a cold start rough engine running, the misfire faults are stored in more than one cylinder of the same bank, all three injectors from that bank need to be replaced.

In case the misfire faults are stored on three (or more) cylinders, then the complete set of injectors (6) needs to be installed.

IMPORTANT NOTE:

For N54 misfire fault complaints during normal engine operation (misfire faults not related to the engine's "cold start"), refer to the following Service bulletins:

B12 05 09 - N54 (E6x) Misfire Faults due to DME Software Error

B12 06 09 - N54 (E9x) Misfire Faults due to DME Software Error

and I also found this one

13 05 08 Rough Idle, Rough Running, Misfiring and loss of power
SUBJECT
Rough Idle, Rough Running, Misfiring and Loss of Power


MODEL
E90, E92 and E93 M3


SITUATION
The customer complains that the vehicle runs rough while idling or driving; the vehicle can misfire; and a loss of power can occur. In some cases, the vehicle's Service Engine Soon lamp is illuminated and fault code 2B23 (Idle-air actuator, regulator monitoring) will be stored in the DME fault memory. In some circumstances, the vehicle's engine control may enter the emergency program and store various misfire faults.

CAUSE
The idle-air actuator or idle circuit has become blocked or restricted, due to an internal separation of the rubber hose located between the idle-air actuator and the intake manifold. The layers of the rubber hose will tear away and restrict the idle-air actuator or one of the idle strips located on each engine bank.

PROCEDURE
On a customer complaint basis, remove the intake manifold in accordance with RA 11 61 050, Removing and installing air intake manifold (S65), to inspect all idle circuit components.



Remove and inspect the hose (1) located between the idle-air actuator and intake manifold. Remove and inspect the idle-air actuator (2). If debris is found, remove the debris, but do not replace the idle-air actuator. Remove and inspect both idle strips. If debris is found inside the idle strips, then both idle strips must be replaced. Whenever rubber hose debris is found in the idle circuit, it will be necessary to replace the rubber hose (1) between the idle-air actuator and the intake manifold as well. The rubber hose (4) located between the idle strips should be inspected and cleaned; do not replace this item.

__________________

Quote:
Originally Posted by elp_jc
That's exactly what my car does... WHEN COLD. Not exactly what I'd describe as a true hard start, but the engine stutters for a second then high-idles fine. I thought maybe that was due to the fact with clutch depressed engine starts cranking right away, without fuel pump priming first, ECU running its diagnostics, etc. But if I turn the ignition on first, then crank the engine it still hesitates before going into high idle. Wonder if all other '08 owners experience the same starting behavior.

I'll take the intake apart mostly for curiosity, and to check everything under there, make sure no oil leaks, and also see what kind of freaking hose is that and how it can disintegrate; that's bizarre. Will report what I find. Will scrutinize the actuator/valve as well.

tonyb635

Bam! Problem fixed!!! I replaced the spark plugs and swapped coil 5 with 6 buttoned her back up and she's running very smooth again. The plug change was so easy it was ridiculous. I read that I sucks, because you will drop a tool and then have to remove the lower panel to retrieve it. The last screw on the engine cover I dropped a small extension abut 2 " in length with a torx on it. I looked for about one hour even pulling the lower panel. I could not find it! So if any of you see it on the road it's mine!!!

pcy

You will find it when you drop the lower panel that's around the trans pan.

5mokem

Tony I took my 550i in last month for the same problem. Mine was coil 5 that was bad. Got it replaced und CPO Warranty. Glad you were able to fix it, and too bad I didn't see this post til now.

tonyb635

Yeah, it turned out to be only the spark plugs. While I had it opened, it was best that I switch coil positions 6 with 5 just incase the plugs didn't do the trick then I could trouble shoot to see if my misfire moved to #5. Lucky for me all was ok at start up. Hopefully it remains that way.

535Dante

My car suffers from the same cold start-up rough idle issue. I have a 2010 535xi. Had the walnut shell blast to clean out carbon and it was covered under warranty about 1k miles ago. Unfortunately didn't fix it.

My spark plugs were changed about 7500 miles ago, you think it's time to change em out again?

JWMich

I had this, too. Rough idle when cold. Pre-50,000 mile first attempt was replace all spark plugs. Did not fix. Continued and got worse over next month. Finally began to run rough off idle and threw some codes that could be looked at. In for service, left overnight so tech could get a cold start. This attempt at the fix was replacement of all injectors. So far seems to have done the trick.

ditka550

I know this may sound too easy however here is my experience. Cold start would produce a rough idle and when backing out of the garage and then driving away the car seemed to hesitate and even feel like it was missing. No CEL ever and this weekend I removed the MAF and sprayed it down with MAF Sensor Cleaner, let it dry and reassembled and now the car idles great and accelerates with just the slighest input from the accelerator. It brings a smile to my face now.....especially as some people posted about the lag that we get when accelerating and then slowing down and hitting the gas again....GONE! Maybe my fix seems too easy, but I can tell you its like driving another car now.....

tonyb635

In my case I finally threw a code that pointed me to the #6 cyl misfire. It would be probably a plug or a coil pack and according to another thing I read possibly an injector. Mine turned out to only be the plug in #6 but I changed all of them. They say to change every 45k but if you are tuned it should be less...

NyC545I

Hi, All... I'm experiencing a similar problem as well, If some one could please chime in I'll appreciate it.
I have a 2009 550i with 55k on the clock, since months ago it's been idling strange between 475rpm-500+ rpm
the needle fluctuates but once you give it gas it's smooth and normal, also when you put it on Drive it shakes even more like a misfire. I unplugged the MAF and it smoothes out it idles at 750rpm but otherwise all is fine. I took it to a well known Indy shop here in NYC and they changed all plugs, coils then MAF and now the throttle body. and I still have the same problem, originally when the check engine light was on the first time apparently it threw bad coil codes later on it something on MAF.
so.... I'm puzzled of what can it be? also when the engine light is cleared it's perfect no issues until, I shut the car off, then I'm back at square one. For the time being I'm running with the MAF unplugged.
Please any advice would very helpful, Thanks