[idle - not a prob.Car now scratched...]Stumbling idle and bucking on warm start

[caslca]

I started getting a problem when starting the car warm. The car has idle which is exactly like the video below. The car is '13 E92 ZCP DCT with 16K miles. It also tends to buck in 1st and 2nd(read that term in a similar post), which seems very much related.

I'm bringing it next week to dealer to troubleshoot this. From what I could gather, it seems to be a tricky one to properly diagnose. I was planning to ask them to check:

* coolant temperature sensor
* fuel low pressure sensor
* possible loose throttle body
* [new suggestion] idle air control valve issue.
* [new suggestion] throttle actuators

Does anyone have any other suggestions I should bring up?

----
A couple other data points:
* The problem has never happened on cold start(or at least I haven't noticed).
* I always drive the car in M(MDM/Sport EDC/Sport+ power) in S4. The first thing I do when I start is hit the M button
* Has never happened after I drive off.
* I don't have any problem accelerating ever, so it doesn't seem to me like a fuel supply issue, and the fuel I use is 91 octane +techron from Chevron. I've been using it from the same gas station for the past 5 years with my 550i (which hated Shell and 74) without any problems so doubtful on the fuel but can't be 100% since i haven't had analysis done.

[AlpineE92M3]

Get a DCT tune, it will take care of the "bucking " problem. My BPM tuNE took care of every problem I had.

[caslca]

Even for '13(mfd April,'13)? I thought the SW issues got ironed out by '11.

[TVMA Doc]

Originally Posted by caslca

I started getting a problem when starting the car warm. The car has idle which is exactly like the video below. The car is '13 E92 ZCP DCT with 16K miles. It also tends to buck in 1st and 2nd(read that term in a similar post), which seems very much related.

I'm bringing it next week to dealer to troubleshoot this. From what I could gather, it seems to be a tricky one to properly diagnose. I was planning to ask them to check:

* coolant temperature sensor
* fuel low pressure sensor
* possible loose throttle body

Does anyone have any other suggestions I should bring up?

Mine does this all of the time as well as the bucking when I try to gently accelerate after a stop (as when making a right hand turn after a stop sign). The local BMW shop says it doesn't do it, even though I've had it happen on a nearly daily basis.

[spiderspider]

Bucking. Yes, that's what mine does. How do I make it not do that?

[///M Power-Belgium]

Watched OP's video,and this situation is not normal !
My car has never done this , even not at the first start up after a hibernation of 2-3 months .
Personal I think it's a bad fuel problem or lack of fuel pressure .
Has the car the same problem during the cold start cycle ?

[tkearns119]

Looks like an idle air control valve issue.

[801M3]

Idle control device or throttle actuators..

[caslca]

Originally Posted by ///M Power-Belgium

Watched OP's video,and this situation is not normal !
My car has never done this , even not at the first start up after a hibernation of 2-3 months .
Personal I think it's a bad fuel problem or lack of fuel pressure .
Has the car the same problem during the cold start cycle ?

The problem has never happened on cold start(or at least I haven't noticed). I always drive the car in M(MDM/Sport EDC/Sport+ power) in S4.

I don't have any problem accelerating ever, so it doesn't seem to me like a fuel supply issue, and the fuel I use is 91 octane +techron from Chevron. I've been using it from the same gas station for the past 5 years with my 550i (which hated Shell and 74) without any problems so doubtful on the fuel but can't be 100% since i haven't had analysis done.

[caslca]

Originally Posted by tkearns119

Looks like an idle air control valve issue.

Originally Posted by 801M3

Idle control device or throttle actuators..

Thanks guys, I'll bring this up to my SA next week.

[///M Power-Belgium]

Originally Posted by caslca

The problem has never happened on cold start(or at least I haven't noticed). I always drive the car in M(MDM/Sport EDC/Sport+ power) in S4.

I don't have any problem accelerating ever, so it doesn't seem to me like a fuel supply issue, and the fuel I use is 91 octane +techron from Chevron. I've been using it from the same gas station for the past 5 years with my 550i (which hated Shell and 74) without any problems so doubtful on the fuel but can't be 100% since i haven't had analysis done.

Than it's probably the idle control , or throttle actuator.
Hope it's not throttle actuator because it's not cheap !
BTW...it's really strange with only 16K on it .
But saw your car is '13 and normaly covered by BMW/warranty .

[tkearns119]

Originally Posted by caslca

Thanks guys, I'll bring this up to my SA next week.

Does the idle bounce everytime at startup? After sitting for several days? Does it cease after a full warm up. In my experience if this has just recently started happening or it is intermittent, I would give it until Spring time and warmer temps. Seems the cold weather/winter fuel mix can cause the valve to "stick" a little easier. If it is happening every time you drive, take her in.

[Stallion150]

My car has been doing this for the past 1.5 years had idle control valve, coolant temp sensor, idle air actuator etc changes without a real fix.
.
I've found if I don't start the car with the a/c on, it rarely occurs now.

[caslca]

Originally Posted by tkearns119

Does the idle bounce everytime at startup? After sitting for several days? Does it cease after a full warm up. In my experience if this has just recently started happening or it is intermittent, I would give it until Spring time and warmer temps. Seems the cold weather/winter fuel mix can cause the valve to "stick" a little easier. If it is happening every time you drive, take her in.

It isn't reproducible, no. It happens 20% of the time or so. In Seattle it has been very springy- temps have been in the 50s since Jan.

[maloo]

Originally Posted by caslca

The problem has never happened on cold start(or at least I haven't noticed). I always drive the car in M(MDM/Sport EDC/Sport+ power) in S4.

I don't have any problem accelerating ever, so it doesn't seem to me like a fuel supply issue, and the fuel I use is 91 octane +techron from Chevron. I've been using it from the same gas station for the past 5 years with my 550i (which hated Shell and 74) without any problems so doubtful on the fuel but can't be 100% since i haven't had analysis done.

Assuming it's not a mechanical problem, I would try a heavy dose of Star Tron in the gas tank.

[tkearns119]

Originally Posted by caslca

It isn't reproducible, no. It happens 20% of the time or so. In Seattle it has been very springy- temps have been in the 50s since Jan.

I agree with Stallion150 above. Start the vehicle without the A/C on. Fill up with 93. Still happens take her in.

[Stallion150]

Originally Posted by tkearns119

I agree with Stallion150 above. Start the vehicle without the A/C on. Fill up with 93. Still happens take her in.

it's a weird phenomenon as its been persistent>1 year without ever escalating into a bigger problem. But yeah, start the car with the A/C off and it goes away.
.
To test the above, I started the car with A/C full blast (2nd start of the day, so a semi- warm start) and the idle surged up and down for 3-4s and then stopped and the car drives 100% normal
.

[caslca]

UPDATE
Well, the dealer said the issue is normal so there's that. I'm ok with that for now since the car has absolutely no issue with power.

On the other hand, they scratched my front well and seem to have sprayed some kind of chemical over the front which left orange spots on my MW. Good thing I took pics all over the car the moment I handed them the keys. Going back tomorrow to see what they can do about the damage...

Here's the SIB for the problem

[Peertwelve]

Which dealer scratched the car? BMW Seattle?

[caslca]

Originally Posted by Peertwelve

Which dealer scratched the car? BMW Seattle?

I will defer answering until I get them to look at it tomorrow, but I'll say this: they did the exact same crap job with my 550i back in 2012. Dropped it off for routine stuff, came back with a gash in the rear well. Looked like The Wolverine didn't quite like my car - decided to use it as a scratch toy. Not only that, they had slapped on some paint to cover it up. I didn't notice until I got home and it was after hours before the weekend. By the time I went to show it to them, felt like I didn't have a leg to stand on since I didn't have pics or anything. They repaired the damage free of charge though and paint work was really good. Did not have to argue at all, just politely explained the situation.

Today, I felt very worried bringing the car in this morning. In fact I almost turned away...This time the damage is to the front bumper (scratch), hood(paint/acid), and front well(paint/acid). Not sure what they'd offer but I took about 20pics all around the car before they took it in.

[caslca]

BTW, does anyone know what might cause spot discoloration on paint? I can't figure out what they might have done... I used my claybar on it but didn't make any difference:

[Agent-GHQ]

Tell us which dealer first! 😒