Rough idle/stall on cold start

[dyintorace]

Folks,

I continue to work my way through my new (to me) ZHP (2004 sedan, 80k miles) and various and sundry issues. I've come across the latest and could use some collective wisdom.

Recently, I had the car reprogrammed by the local BMW dealer, to address a stutter under throttle while in 5th or 6th gear and a tendency to want to stall when decelerating into a stop while clutched in. Good news...both issues were solved. The bad news is the car immediately developed another habit. When starting the car while cold (overnight or anything longer), the car will start, start to idle roughly and then either catch itself or die. Usually, the longer it's sat, the more likely it is to die.

I have the car at my mechanic's currently. I had already planned on having him change all the fluids (already did the oil, now he's on to the trans, diff, brake, coolant, steering) as well as replace a leaking pinon seal. We also decided to change the fuel filter, given the car's mileage. He experienced the cold start issue (it died on him), so he took it to the dealership for me, thinking it is a programming issue.

While that is going on, I'd love your thoughts on what it could be. Any thoughts?? :(

Thanks, Tucker

[danewilson77]

ICV.

Unrelated... Have him check disa as well.

Are you changing plugs?

Maybe check fuel pressure at the rail?

HTC Thunderbolt+TT

[dyintorace]

ICV.

Unrelated... Have him check disa as well.

Are you changing plugs?

Maybe check fuel pressure at the rail?

Plugs were changed at Inspection II, not terribly long ago. I'll offer the other suggestions though. Thanks for the ideas!

[CERF04ZHP]

I'd like to resurrect this one if I may... Experiencing nearly the same symptoms, except I haven't stalled yet. Every cold morning that I start it, it drops down to 500-600 rpms and coughs/chugs a couple of times, then jumps back up to a normal "cold" idle. If I stab the throttle quickly right after I start it, I can avoid the temporary low idle. Replaced fuel filter approx. 20k ago, I'm thinking replace DISA/clean ICV? Plugs haven't been done in 60k+ either... Mayyyyybe do those too?

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[alexandre]

I'm having the same problem with new DISA, clean ICV, intact intake boots, 20k miles plugs, < 20k fuel pump and filter, Techron 2k ago and < 1k oil. (I didn't do all of this to fix it lol it's just the state of my car currently)

Starts at 1100, drops to 800, up and down 800<>1100 and stabilizes at 800 after. ICV did a huge difference - it only 'coughs' twice until it stabilizes, while it struggled 6-7 times before. Improved MPG as well. Takes 45 minutes, just do it :)

Next steps are O2 sensors, which are original (and thus due twice already on my car based on BMW's recommended replacement interval), reverting my ECIS CAI back to a stock airbox with a new filter. I also need a DME upgrade to the latest version. If you want to check your O2's the manufacture date is on the connectors under the engine cover.

Let me know your progress - I'll do this as well.

[CERF04ZHP]

I'm having the same problem with new DISA, clean ICV, intact intake boots, 20k miles plugs, < 20k fuel pump and filter, Techron 2k ago and < 1k oil. (I didn't do all of this to fix it lol it's just the state of my car currently)

Starts at 1100, drops to 800, up and down 800<>1100 and stabilizes at 800 after. ICV did a huge difference - it only 'coughs' twice until it stabilizes, while it struggled 6-7 times before. Improved MPG as well. Takes 45 minutes, just do it :)

Next steps are O2 sensors, which are original (and thus due twice already on my car based on BMW's recommended replacement interval), reverting my ECIS CAI back to a stock airbox with a new filter. I also need a DME upgrade to the latest version. If you want to check your O2's the manufacture date is on the connectors under the engine cover.

Let me know your progress - I'll do this as well.

Will do, thanks Alexandre.

[johnrando]

Beside the DISA, fuel stuff, etc., it may sound crazy but check your battery. A weak battery can wreak havoc on these cars, including producing a rough idle. Go figure.

[danewilson77]

OBC whatcha go?

[CERF04ZHP]

Beside the DISA, fuel stuff, etc., it may sound crazy but check your battery. A weak battery can wreak havoc on these cars, including producing a rough idle. Go figure.

Did not know that.

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[alexandre]

Battery's a month old on my car. Did make a difference on the car's behavior at startup.

[echo46]

I had idle problems and did everything. ICV clean, throttle clean, replaced plugs, replaced intake boots, replaced CCV and all it's hoses, checked DISA, checked DISA twice, changed fuel filter, changed fuel pump and changed fuel sender. Glad I did all that but it did not help my rough idle issue. Then I started looking at fuel rail pressure. Finally, just pulled the fuel rail and all the injectors. I found that one injector had a very slow leak and would drip gas. Changed the injector and car starts flawlessly.

The only difference is that my car started fine on the first start up of the day, I just had the the problems on every subsequent start up of the day.

[alexandre]

That's interesting. I'm seeing the inverse behavior as you though - it's rough on the first start of the day, and fine for subsequent starts (even after sitting still for a few hours while I'm at school). How hard is it to access the fuel rail ?

[CERF04ZHP]

That's interesting. I'm seeing the inverse behavior as you though - it's rough on the first start of the day, and fine for subsequent starts (even after sitting still for a few hours while I'm at school). How hard is it to access the fuel rail ?

Same here. First (cold) start of the day is rough. Every other start following the first is fine.

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[echo46]

Well it's a bit of a PIA as you have to be very careful as to not damage any of the CCV hoses that are around there. When you are removing the rail, remember to release the pressure at the schrader valve, then you have to pry the rail off which can be tough. I think I have a thread on here where I explained how I did it let me check and I will link it. However, before pulling the rail and dealing with gas issues etc, make sure you don't have a vacuum leak somewhere. Oh and clean the icv and throttle.

Try this link. Great DIY on fuel injectors. Oh, have to drop a foot note to DW as he found this one for me, werd.

http://%3cbr%3ewww.bimmerfest.com/forums/showthread.php?t=571302

[CERF04ZHP]

Also, of note... When I do cold start it and it bogs down, my belts chirp a few times. Belts have less than 20k on them. Maybe just a result of low rpm?

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[alexandre]

I just finished doing my O2's before my first start of the day... They pretty much fixed the issue. Look at all that crap! echo, I checked my injectors at the same time and everything seemed fine. Thanks for your help though :)

http://imageshack.us/a/img99/4843/photo2012100593143am.jpg

They had 210k miles on them and were well overdue. I still have a slight dip, but it's probably the ECIS intake that's dirty. I'm gonna consider it fixed on my end. Still curious on your solution though.

[alexandre]

Try cleaning the MAF sensor as well.

[echo46]

Glad you found and fixed the problem.

[Go Horns!]

I am having this problem now. I just replaced the battery. Made no difference. Hard start when cold with a rough idle right afterward. Once it revs for a bit, everything is fine. Starts up fine at lunch and after work.

Plan is to clean the MAF and check the intake boot for cracks.

Car has 41K on it.

[danewilson77]

You guys should check/clean/replace intake filter on this as well.

Sent from Williamsburg, VA USA

[alexandre]

One thing I've noticed is that if I let the fuel pump prime before starting (that weird noise you hear when you turn your key to pos. 2) it starts up super smooth, while if I go from pos. 0 to start immediately it does idle rough for a few seconds. Might wanna check if this is what's going on (and if so I'll guess it's normal ?)

[alexandre]

Well... Turns out it hasn't completely gone away just yet. Now with all the maintenance I did (ICV clean, DISA clean, MAF clean, reverted to stock airbox w/ new filter, checked all intake boots - no leaks, new O2 sensors, ran a bottle of techron) it starts fine on most mornings but I park in a heated garage most days and when I leave in the evening it still starts rough. Doesn't happen all the time though, I'm not able to trace an accurate picture of when/where it happens. I'm thinking there's a bad injector somewhere - when I checked them while doing O2's the car had ran for a few minutes so maybe it's a very slow leak that only occurs when it's warm. Car has never smelled of gas since I've had it.

I remember running codes this summer after the car sat for 5 days and I had these - the camshaft codes are still there but don't trigger SES. I cleared them Monday and they still came back.

DME* -> 28B6/81 - Inlet-camshaft bank1: mechanically
28DD/84 - Air mass system - don't bother - MAF just needed a cleanup
28BC/81 - Exhaust camshaft bank1: stiff
28B8/81 - Exhaust camshaft bank1: mechanical
2747/82 - Mis-fire cylinder 4 - never seen that again 3,000 miles after clearing

Say I have a slow leak on injector #4, would it be possible that the cylinder was flooded enough after 5 days to cause a misfire at startup ?

[JKO_ZHP]

I had the same rough idle when first starting it up in my previous '05 325Ci, got a new DISA, crank case, and intake manifold (I think).
Problem solved

[alexandre]

Car sat for 2 days in a heated garage this weekend. Here's a video of cold startup:

https://www.dropbox.com/s/52v04zw6eonym5x/Video%202012-10-28%206%2011%2027%20PM.mov

[danewilson77]

Car sat for 2 days in a heated garage this weekend. Here's a video of cold startup:

https://www.dropbox.com/s/52v04zw6eonym5x/Video%202012-10-28%206%2011%2027%20PM.mov

How long until it stabilized around 700 rpm?

[alexandre]

From there it just goes down smoothly and doesn't hiccup at all. Off the top of my head I'd say 30 seconds. Let me go grab another video, maybe it cooled down enough to reproduce the symptoms.

[alexandre]

This is after the car sat for 1 hour in the 54 degree night. Timeline:

- 1810 drive for 20 mins. 1st video was taken in interior parking at startup.
- 2130 idled for 5 minutes to check the CVV using the ziploc bag oil cap technique - was as expected for a healthy CVV. Engine acted like on 1st video.
- 2230 started and took this video.

http://tinyurl.com/9xmbtcq

Looks perfectly fine to me. I filmed a bit inside the engine bay to see if any weird noises might be present. This is so weird.

[aurelius]

Same issue with a 325i and I too found it can be managed as described in post #21.

Wondering tho whether to replace fuel pump or the "sucking jet" piece described in the realoem diagram.

Anyone know if fuel pressure test would indicate which is the culprit?

[alexandre]

I updated my DME today to BMW's latest version (7561520). It's supposed to help a lot with idle and throttle response issues. Will report back to see if it fixes my startup problem.

[nike001]

I had a similar problem last night. Wasn't really a cold night and the car was in the garage and it didn't seem too happy to start, and then ran rough.

But reading this thread made me remember when I was leaving my dads the other night where temps were in the mid-upper 30's. I got in it and put the key in and immediately turned it to crank it. Car did nothing for 1-2 seconds and then turned over a bit. By the time it decided to turn over I was already turning the key back to pos 0. Tried it again and it started normally with no lag after I put it in pos 3.. or whatever the crank part is.

[Hermes]

^ Dalton, you honestly should get used to priming your FP... I think it honestly lets it last years longer than normal operation if you get accustomed to that technique.

[nike001]

^ Dalton, you honestly should get used to priming your FP... I think it honestly lets it last years longer than normal operation if you get accustomed to that technique.

Yeah I do it a lot. The other night I didn't because it was just so damn cold lol. I HATE the cold.

[BRGcoopahS]

Battery's a month old on my car. Did make a difference on the car's behavior at startup.


^ Dalton, you honestly should get used to priming your FP... I think it honestly lets it last years longer than normal operation if you get accustomed to that technique.


Are you talking about turning the key to let the fuel pump start and then starting it? I just remembered that the other day. I think I'll start doing that from now on, especially with this cold weather coming up. Cars always feel more fragile in the cold.

Mine actually had a super rough idle until it warmed up after not driving it for a week. This was when the hurricane hit and there was long gas lines. I just drove the mini instead.

[nike001]

^yes

Put the key in pos II and you'll hear the fuel pump turn on. Then after your car beeps a few times you can turn it on. It usually turns right on with little to no cranking.

It's like priming our glow plugs... Except we don't have diesels :P

[06ZhP]

Sorry to revive an old issue.

I've been having rough idle problems intermittently (Less than 5 each winter). I only see the issue sometimes when temps. drop well below 30F and also when the car sits for a few days. I haven't tried to fully tackle the issue and wanted to get people's advice.

I got a chance to record this mornings episode (see video below). It felt like a fuel starvation problem. The idle maintained at 700rpm +/- but the engine was struggling to keep turning, similar to when one of the plugs is disconnected.


http://s1105.beta.photobucket.com/user/06zHp/media/324F7FE8-E2CB-4DBC-AB7A-1985468F45C8-13412-000012635B2D0D7D.mp4.html

The car has had Service I and II. I have changed the plugs at 55K and upper intake boot at 75k. Other than that nothing has been touched. I'm guessing O2/ICV/DISA...

Any help anyone can provide would be great!

[danewilson77]

The car has had Service I and II. I have changed the plugs at 55K and upper intake boot at 75k. Other than that nothing has been touched. I'm guessing O2/ICV/DISA...

Any help anyone can provide would be great!

My guess as well. Throw a code reader on it.

[06ZhP]

Thanks Dane, planning on it as soon as I get home from work...

[aurelius]

May have been posted earlier in this thread but there is a ton of good info HERE (http://forum.e46fanatics.com/showthread.php?t=897616). The guy doesn't get to his main point until well into the long post but it's a cheap fix (one of the CCV hoses).

Also worth checking, considering your symptoms, is the link early in that post to fuel pump issues. Specifically the "soft failure" thereof.

EDIT: your video's audio sounds exactly like my car after the fuel pressure regulator was replaced. Replaced it myself at a DIY day at a local shop and once finished was checking out some other cars. A little later one of the techs went to back my car out of the bay and not realizing what I had done to it, he didn't prime the pump. Engine started but the misfiring was enough to generate a CEL plus a code (which they of course cleared for me). Point being you may have a fuel pressure issue.

[Go Horns!]

Update - Cleaned MAF, throttle body, and ICV, and replaced DISA and intake boots. IDLE is back to normal. I think my problem was the intake boots because the lower one had a good-sized gash and I was getting lean codes.

[danewilson77]

Update - Cleaned MAF, throttle body, and ICV, and replaced DISA and intake boots. IDLE is back to normal. I think my problem was the intake boots because the lower one had a good-sized gash and I was getting lean codes.

Good news Amigo.

[echo46]

Good find. Glad it is back to normal. Those vacuum leaks can certainly be pesky.

[06ZhP]

Point being you may have a fuel pressure issue.

Thanks for the link! I an defiantly considering it being a fuel pressure related issue.

[06ZhP]

Update | Code read - P0306 = Cylinder 6 Misfire Detected

I've read the codes before and im pretty sure its been a misfire that ive been having. How often are injectors replaced? I didn't see in the write-up...

As soon as I get a chance I will give a thorough cleaning/checking of the intake/MAF/Throttle Body/ICV/DISA. When I replaced the upper intake boot, I poked around and everything seemed kosher. I'll report back with my findings...

[danewilson77]

Update | Code read - P0306 = Cylinder 6 Misfire Detected

I've read the codes before and im pretty sure its been a misfire that ive been having. How often are injectors replaced? I didn't see in the write-up...

As soon as I get a chance I will give a thorough cleaning/checking of the intake/MAF/Throttle Body/ICV/DISA. When I replaced the upper intake boot, I poked around and everything seemed kosher. I'll report back with my findings...

Swap coils around and see if code follows that coil pack to a new cylinder.

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[aurelius]

^^ Good suggestion.

If you remove the DISA, ICV, etc., 3 other cheap things to consider before doing so:

1. DISA repair kit from German Auto Solutions (which includes a nice o-ring for where DISA meets intake).

2. New rubber grommet for where ICV mates to motor.

3. New lower intake boot.

[06ZhP]

Swap coils around and see if code follows that coil pack to a new cylinder.

Good thinking! The only problem it that I will have to wait weeks if not months for this problem to show up, but none the less worth the effort.

[06ZhP]

Was thinking of ordering those as I was reading the thread you posted. Hopefully it's a simple leak issue..

[aurelius]

Click HERE (http://forum.e46fanatics.com/showthread.php?t=773551) for an E46f thread that gets straight to the point re the lower oil drain hose connecting the CCV to the dipstick tube. Bottom line is it fails regularly, causes a rough idle (especially in cold weather), may save you from full CCV rehab, and is cheap/easy. Note: in addition to the part number mentioned in the DIY, there's another, insulated version of that hose. Same price as non-insulated.

Amazing how many respondents to that thread have found this hose to have disintegrated.

[06ZhP]

Click HERE (http://forum.e46fanatics.com/showthread.php?t=773551) for an E46f thread that gets straight to the point re the lower oil drain hose connecting the CCV to the dipstick tube. Bottom line is it fails regularly, causes a rough idle (especially in cold weather), may save you from full CCV rehab, and is cheap/easy. Note: in addition to the part number mentioned in the DIY, there's another, insulated version of that hose. Same price as non-insulated.

Amazing how many respondents to that thread have found this hose to have disintegrated.

Thanks!

[ELCID86]

So, Alex, what was the fix for your car? Sorry if I missed it above. I have a hesitation under acceleration at low RPM and especially when it's cold (engine and ambient temp). Justin previously recommended pre-cat O2 sensors and I think VANOS (or vise versa). I bought the sensors but have not installed them yet and was about to buy a Dr. V, but don't want to sink the money into it if that is not the root cause. My intake boots are new, ICV and DISA inspected and cleaned. I read a few threads on e46f about the Camshaft Position Sensor (https://www.ecstuning.com/Search/SiteSearch/12147539165/ES1899282/) being the possible cause. I plan to stop by Advance Auto to see if there are any codes on the way home tonight (no SES light).
(https://www.ecstuning.com/Search/SiteSearch/12147539165/ES1899282/)

[ELCID86]

So, Alex, what was the fix for your car? Sorry if I missed it above. I have a hesitation under acceleration at low RPM and especially when it's cold (engine and ambient temp). Justin previously recommended pre-cat O2 sensors and I think VANOS (or vise versa). I bought the sensors but have not installed them yet and was about to buy a Dr. V, but don't want to sink the money into it if that is not the root cause. My intake boots are new, ICV and DISA inspected and cleaned. I read a few threads on e46f about the Camshaft Position Sensor (https://www.ecstuning.com/Search/SiteSearch/12147539165/ES1899282/) being the possible cause. I plan to stop by Advance Auto to see if there are any codes on the way home tonight (no SES light).
(https://www.ecstuning.com/Search/SiteSearch/12147539165/ES1899282/)

Ran a some concentrated Techron thru her and stopped to scan it. No codes.


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[ELCID86]

I heard from Alex via text. He's busy finishing up this semester.

His car had issues with the Vanos. PO had Installed a spring from the exhaust side in the intake side.

I have a Beisan kit I bought from Bill so it's probably worth the gamble to try that repair first. And do the O2 sensors and inspect cam position sensor "while I'm in there".


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