Missing\rough idle at cold start

[ianc]

Hi Folks,

I've noticed just in the past couple of weeks that I'm getting what seems to be a slight miss and some roughness in idle immediately after a cold start. It seems to smooth out and run fine after 10 or 15 sec. I don't notice any loss in in power or economy as of yet.

The car is a couple of months out of warranty (of course) with about 41K on the clock. No tune.

I don't currently have any means of reading codes, but I suppose it will be necessary to get something soon, seeing as how I don't have mama BMW looking after me any more...

Does this type of symptom usually throw a code? Should I buy a reader to check it out?

Thanks for any insight; I've been out of the car-working-on biz for the duration of the warranty, but I guess I better start thinking about it again now...

ianc

[vivanapoli806]

Get something to read the code and see which cylinder is misfiring. Then switch the coil pack to diff cylinder and see if the misfire switches to the cylinder u put it in. If not it's most likely spark plug. At 41k ur about use for new plugs they get changed out around 45k

[ianc]

Thanks for the response Viva! Will acquire a scanner and do as you suggest,

ianc

[Stvee]

I'm at 39k and have this going on as well. I've got a set of spark plugs on the way since they're due to be changed. If that doesn't work I'll look into the coils, then injectors.

The thing was, I scanned mine about a week ago and it didn't have any codes other than something related to the battery which was probably because I had the battery recall done recently.

[GMD]

My car does the same thing, but it seems to come and go depending on what flash I'm using. Seeing that your car does not have a tune, I am interested to hear your findings. My car has recently been walnut blasted and has a fresh set of spark plugs.

[Adam135]

40k and I have same issue. My plugs are new. 3 out of 6 injectors are new. Original coil packs I'm sure. Cobb tune.

[FactorX81]

I have a similar issue at 32k my idle is a little rough and even after I have driven the car for a while it will go up and down about 300rpm almost like turning the air conditioner on and off. I had 3 injectors replaced last year under warranty due to leaking and valve cover replaced. The car runs fine otherwise no loss of power and no codes thrown. I first noticed it during the winter but thought maybe it was due to the weather. I did a 2 day HPDE in April and want to do another one next month but I'm not sure if this is a real problem or not and don't want to damage anything.

[ianc]

Thanks for the further info guys; seems like not that uncommon a problem...

Stvee, would be interested to hear whether the plugs make any difference for you, although it seems not to have helped others. Guess I ought to just go ahead and order up a set anyway...

ianc

[Hellkite]

I had the same problem I put teckron in my tank for 3 times when I filled up, one bottle every time you fill the tank. have you ever had your intake cleaned yet? 30 to 40k is about the time to do it.

[headsup7up]

I have the same problem. Ive replaced all 6 plugs, all 6 coils, all 6 injectors, injector/ coil wire harness, long block and it still misfires.

[Spoolin Montego]

Originally Posted by headsup7up

I have the same problem. Ive replaced all 6 plugs, all 6 coils, all 6 injectors, injector/ coil wire harness, long block and it still misfires.

fuel pump been replaced? I'm almost to in your boat. Replaced 6 sparks, 6 coils, 6 injectors and STILL I have the misfire

[headsup7up]

Originally Posted by Spoolin Montego

fuel pump been replaced? I'm almost to in your boat. Replaced 6 sparks, 6 coils, 6 injectors and STILL I have the misfire

no the fuel pump is still the original. lol i keep asking bmw if that could be it but they say no. Every other thread ive read seems to point to a issue with the injectors but this is my second new set. Its weird becuase ill replace the coils and plugs, the car will be perfect for a few hundred miles but then the misfire comes back. something is ruining these coils.

[MightyMouseTech]

My 2013 has done this since the day it was new. Cold start, 1200 RPM, wait a few secs, idle drops to 900 or so, car shakes for about 10 secs, then idle stabilises. Figured it was normal. Not something I am going to worry about.

[Spoolin Montego]

Originally Posted by headsup7up

no the fuel pump is still the original. lol i keep asking bmw if that could be it but they say no. Every other thread ive read seems to point to a issue with the injectors but this is my second new set. Its weird becuase ill replace the coils and plugs, the car will be perfect for a few hundred miles but then the misfire comes back. something is ruining these coils.

Dude my car has the exact same issue!!

BMW keeps refusing to replace my HPFP as well.

[Stvee]

Originally Posted by ianc

Thanks for the further info guys; seems like not that uncommon a problem...

Stvee, would be interested to hear whether the plugs make any difference for you, although it seems not to have helped others. Guess I ought to just go ahead and order up a set anyway...

ianc

Plugs didn't fix it. I'll have to re-check to see if it is throwing any codes yet.

On an unrelated note, I drove the car without the cowl on for a few minutes after I put the plugs in. The turbos are so much louder with that off.

[ianc]

OK, just checked the codes, and it looks like it did throw 4 using the BMWhat Android app:

002E9F - Oil condition sensor/Failure oil quality sensor/Oil level sensor error

0029CD - Misfire detection cylinder 1 in 1 Firing order/Misfire detection cylinder 1 in 1.Zuendreihenfolge/Intake air temp sensor temp is too low/Failure detection cyl. 1

0029CF - Misfire detection cylinder 3 in 2 firing order/Failure detection cyl.5/Misfire detection cylinder 3 in 2.Zuendreinfolge

0029CC - Misfire detection error summation/Intake air temp sensor temp is too high/Failure detection checksum/Central control timeout

Don't really know where to go with these. Haven't found anything about them online yet. Oil level sender seems to be working in car...

Any ideas?

ianc

[ianc]

Oil level sender seems to be working in car...

Hmmm... Maybe not. I noticed I was a little low, so added a bit this AM (about 4 oz). No change in sensor level displayed in dash. Dammit...

ianc

[135iDCTFan]

Anyone else noticing a rougher idle (cold or hot)? I'm not seeing any codes, stalls, rev bouncing or anything else being off, but there seems to be more vibrations during idling (i.e. waiting at a red light).

It's hard to accurately describe, but I would compare it to the kind of repetitious engine "shake" you'd feel from an older (but well tuned) V-8. It is not quite this extreme, but it has that similar rumbling feel at idle (about 700 rpm).

I going to be out of warranty in October (only 15K miles), so maybe I am just being overly critical. Thoughts??

PS--I am running 93 Shell gas, from a few different stations, so I'm pretty sure it is not the gas.

[ianc]

I'm kind of getting that too. Not very extreme, but not a silky smooth idle either. It's been doing that for a long time while the cold start thing has started fairly recently.

Got a set of BMW plugs on order, so we shall see...

ianc

[135iDCTFan]

Thanks - Good to know! I was thinking new plugs might be in order too -- although initially just related to my poor gas mileage, but the rougher idle could go hand in hand.

Please let me know if the new plug helps.

[ianc]

Did the plug update over the weekend and the improvement seems negligible, if in fact there is any. One thing I did notice, is that I seem to need to give it slightly less gas when taking off from a start as I let the clutch out, so maybe just a slight bit more low end oomph. Another thing I did notice was oil down my plug holes however, so now I'm wondering if that may be related in some way, either as a failure mode of the coil packs, or just interfering with ignition as oil leaked in from VC gaskets?

Not sure...

ianc

[milocher]

Originally Posted by ianc

Did the plug update over the weekend and the improvement seems negligible, if in fact there is any. One thing I did notice, is that I seem to need to give it slightly less gas when taking off from a start as I let the clutch out, so maybe just a slight bit more low end oomph. Another thing I did notice was oil down my plug holes however, so now I'm wondering if that may be related in some way, either as a failure mode of the coil packs, or just interfering with ignition as oil leaked in from VC gaskets?

Not sure...

ianc

Oil in those plug holes is almost guaranteed to be a cracked Valve Cover Gasket. I had mine replaced under warranty for the same issue (oil in plug channels), and it didn't do anything to correct my crappy cold starts or idle.