RPM bouncing between 400-1k on cold start..ISSUES?

[ES_TRADER]

this morning on a cold start, i fire it up, and immediately drive off...about 100 feet away, there's a gate i have to stop at to wait for it to open on my driveway and while stopped and waiting for it to open, i noticed that my car felt like it was going to stall and die...the rpm bounced up and down pretty violently from 400 RPM to 1k...car is DCT with 10k miles on it.

ever since the car was brand new, i did notice a slight quick dip in the rpm after about 1 min on a cold start BUT the dip is very quick and comes right back up and only happens ONCE...the only difference this morning is that the rpm needle began to fluctuate a few times before the 1k engine speed was sustained...No faults were thrown...will this prove to become a major issue? anyone have any ideas?

i tried to search but couldnt find anything really conclusive...i drove the car around for a few blocks and couldnt reproduce it...just kinda felt normal.

[Krozi]

I am pretty positive its the ICV or "Idle Control Valve".

It's a fairly common problem and should be replaced under warranty no questions asked.

[ES_TRADER]

Originally Posted by Krozi

I am pretty positive its the ICV or "Idle Control Valve".

It's a fairly common problem and should be replaced under warranty no questions asked.

does the car have to throw a fault to have this replaced?? or do i just call them and set it up? im pretty sure they wont just take my word for it.

is there any way to reproduce this or you just open it up and see that its defective?thx

[Krozi]

Originally Posted by richpuer

does the car have to throw a fault to have this replaced?? or do i just call them and set it up? im pretty sure they wont just take my word for it.

is there any way to reproduce this or you just open it up and see that its defective?thx

It really depends on the dealer, some dealers will deny any issues and send you on your way. Other dealers who know that this is a common problem will just go ahead the replace it.

Maybe they will request to keep the car overnight so they can replicated the issue in the morning.
Maybe just wait till it happens more often and then go to the dealer.

[1Sleeper]

My car does that, I kind of like it, sort of a lumpy cam kind of thing. Goes away within minutes of the car being on though.

[pbonsalb]

Someone else just complained about a similar fluctuating idle on cold start. His dealer apparently replaced the VANOS. A properly running car won't do this. It will cold start at a higher idle and then taper down to stock. The time and rpm depend on the cold. There should be no significant fluctuation in idle rpm. The car will sound a little mean and rough for 30 seconds on cold start because the air pump is turned on for emissions.

[ES_TRADER]

well..just spoke to a couple SAs...from my description to them it seems normal and they are willing to take a look at the car but nothing will be done unless it throws a fault...if i insist, one dealer said they will open up a puma case for it but im pretty sure my car would be sitting for days, if not weeks...so ill just keep an eye out and drive it till it goes into limp mode to get the code...will update here

[Grail05]

My advisor said the same so I'm waiting as well but still not showing any codes it's been a month.... Even drive my car hard and it made my car run better...lol

[e92zero]

Hi, I have just started to notice this on my car also. I have about 24k miles on my car. Happened 2 x the last couple of months when it's really cold and I left the car outside for the whole day. If I start driving off right away (like 10-15 seconds after start up), at the first stop sign that I get to, the idle would jump between 500-800. Never feel like it wants to stall and will go away if I just let it do that for maybe 10 seconds. If I let the engine warm up for 30 seconds or so before driving off, this won't happen. Sean05/Richpuer, does your car need any fix or it runs perfectly fine as time go on. Thanks in advance.

[-=Hot|Ice=-]

Seems to be a common problem on the M3. I think it's the Idle Control Valve.

[w00tw00t]

Originally Posted by richpuer

this morning on a cold start, i fire it up, and immediately drive off...about 100 feet away, there's a gate i have to stop at to wait for it to open on my driveway and while stopped and waiting for it to open, i noticed that my car felt like it was going to stall and die...the rpm bounced up and down pretty violently from 400 RPM to 1k...car is DCT with 10k miles on it.

ever since the car was brand new, i did notice a slight quick dip in the rpm after about 1 min on a cold start BUT the dip is very quick and comes right back up and only happens ONCE...the only difference this morning is that the rpm needle began to fluctuate a few times before the 1k engine speed was sustained...No faults were thrown...will this prove to become a major issue? anyone have any ideas?

i tried to search but couldnt find anything really conclusive...i drove the car around for a few blocks and couldnt reproduce it...just kinda felt normal.

exact same thing happened to me - my ICV was faulty and dealer replaced it no questions asked...

[ES_TRADER]

Originally Posted by e92zero

Hi, I have just started to notice this on my car also. I have about 24k miles on my car. Happened 2 x the last couple of months when it's really cold and I left the car outside for the whole day. If I start driving off right away (like 10-15 seconds after start up), at the first stop sign that I get to, the idle would jump between 500-800. Never feel like it wants to stall and will go away if I just let it do that for maybe 10 seconds. If I let the engine warm up for 30 seconds or so before driving off, this won't happen. Sean05/Richpuer, does your car need any fix or it runs perfectly fine as time go on. Thanks in advance.

Well I called the dealer about this and they said if it were the idle control valve, it would throw a code and get worse over time.

What I have noticed was this:

On a cold start, if I drive off immediately after firing the on button, and stop at my gate a few hundred feet down waiting for it to open, it will do the rpm bounce. Basically I'm still driving with the cat warm up cycle.

However, if I fire her up and let it idle in my garage until it finishes the cold start cycle, then it will not do the rpm bounce.

This leads me to conclude that it does this as the car is warming up. SA also told me that when car is cold, it uses up alot power before everything gets working so putting car in reverse after starting her up could affect the process of warming cats..either way it hasn't got worse, no codes and car drives fine.

[ES_TRADER]

Originally Posted by w00tw00t

exact same thing happened to me - my ICV was faulty and dealer replaced it no questions asked...

Did it throw a code? How did they know it was faulty? Did it get worse over time?

[e92zero]

^Richpuer. I think I am in the same boat as you. I will just leave it for now and remember to let it warm up for a bit longer. Thanks for the reply.

[ploo]

I had a similar problem and was convinced it was my idle control valve. On cold start, my car would nearly stall and idle very roughly until I warmed the cats up. However, the dealership found no ECU faults and suggested it might be a batch of bad gas, especially as additive formulations do change around this time of year for the winter season.

Sure enough, the problem went away with gas from a different station (Chevron). Who knew the solution could be so simple?

Good luck!

[quads]

Mine does the same thing and the cold it gets the bouncing gets worse. Once it warms up it's all fine. Another thing that doesn't help is the gas companies mixing a different mixture of gas for the winter - I heard it's not that great for cars but they do it for emissions purposes - maybe that is also part of it. I see lots of these threads pop up lately...

[e92zero]

^thanks guys. That's good to know.

[M3PO]

Mine is in the VERY early stages of needing a new ICV and I only have a few months left on my warranty. I think I'm gonna end up paying for this out of pocket. FML.

[PKM3]

Originally Posted by estrader

Well I called the dealer about this and they said if it were the idle control valve, it would throw a code and get worse over time.

What I have noticed was this:

On a cold start, if I drive off immediately after firing the on button, and stop at my gate a few hundred feet down waiting for it to open, it will do the rpm bounce. Basically I'm still driving with the cat warm up cycle.

However, if I fire her up and let it idle in my garage until it finishes the cold start cycle, then it will not do the rpm bounce.

This leads me to conclude that it does this as the car is warming up. SA also told me that when car is cold, it uses up alot power before everything gets working so putting car in reverse after starting her up could affect the process of warming cats..either way it hasn't got worse, no codes and car drives fine.

I spent 3 months taking video of poor cold starts on my 2010 E92 M3 so I could show the BMW technicians the issue. Even though rough cold starts are expected and very normal during the lean run cycle that heats up the catalytic converters quicker), the real question is just how rough should they run cold. I was adamant mine was worse than normal. The BMW master tech (once the issue was elevated from the dealer) initially stated it was normal behaviour, no fault codes registered and in normal operating range. However the dealer took a great initiative and diagnosed the components after seeing a more recent video where the engine really struggled to start in the first 10 seconds. Although the car did not throw any fault code to date, a comprehensive analysis of the ICV showed a fault on one of the ICV diagnosis tests and therefore BMW replaced the ICV under warranty. It is unknown why a fault code was not recorded but certainly one that the software engineers want to consider in the next software update. The replacement of the ICV has resolved the issue (rough dipping and bouncing revs approximately 500-1200rpm on random cold starts and on one occasion difficulty firing up - prolonged cranking). The problem existed more so after leaving the car for at least two days and ran perfectly fine after the first 30 second lean cold start routine. The spark plugs were also replaced as they exhibited some decay, however most of the issue stemmed from the ICV. I'm most grateful there was a top mechanic at my dealer willing to take to the diagnosis and resolution so meticulously. You can appreciate the complexity of these types of issues and the numerous causes for these symptoms and not suggesting to tell BMW that they can get things wrong, but it really helped them to see video footage to assist with their diagnosis; I had also provided them startup voltage footage to show the battery was okay. I think patience was the key to resolving this one!

[72dan]

I am having similar issues. I had the problem while under warranty but the dealer said they didn't notice it. My car just went out of warranty less than a month ago.

I went to the dealer where I bought the car, Bob Smith BMW and they told me while under warranty that they couldn't look at it unless I bought a $299 fuel injector cleaning. I complained to BMW USA and they said they would have someone from Bob Smith BMW get back to me which they didn't

BMW USA said take it to another dealer and they "may" be able to help me out with it. So I went to Rusnak BMW in Thousand Oaks and they said no problem and set an appointment. Then when I showed up they asked me to sign a paper authorizing them to charge me $145 an hour to diagnose and if BMW USA said they would help out we could discuss it after the fact.

I am really disguisted. When I put on 19' wheels and Pilot Super Sports and got my first flat I was denied the included road side service because they weren't original wheels/tires. What does that have to do with a screw in the tire?

Dead battery, "we will try to be there in an hour but it may take longer" Don't bother, I sent someone to Pep Boys for jumper cables.

Now I just sold my Toyota Tundra and need an SUV and BMW says what can we do to earn your business?

[thekurgan]

Originally Posted by 72dan

I am having similar issues. I had the problem while under warranty but the dealer said they didn't notice it. My car just went out of warranty less than a month ago.

I went to the dealer where I bought the car, Bob Smith BMW and they told me while under warranty that they couldn't look at it unless I bought a $299 fuel injector cleaning. I complained to BMW USA and they said they would have someone from Bob Smith BMW get back to me which they didn't

BMW USA said take it to another dealer and they "may" be able to help me out with it. So I went to Rusnak BMW in Thousand Oaks and they said no problem and set an appointment. Then when I showed up they asked me to sign a paper authorizing them to charge me $145 an hour to diagnose and if BMW USA said they would help out we could discuss it after the fact.

I am really disguisted. When I put on 19' wheels and Pilot Super Sports and got my first flat I was denied the included road side service because they weren't original wheels/tires. What does that have to do with a screw in the tire?

Dead battery, "we will try to be there in an hour but it may take longer" Don't bother, I sent someone to Pep Boys for jumper cables.

Now I just sold my Toyota Tundra and need an SUV and BMW says what can we do to earn your business?

Just pick up a couple of bottles of techron concentrate plus, run them through. RPM bouncing isn't always the ICV, many times, it's bad fuel. If the techron doesn't do a thing, then you may have to spend some money for a diagnosis before you start swapping parts.

[fuddman]

Originally Posted by 72dan

I had the problem while under warranty but the dealer said they didn't notice it.

Did the car (while idling erratically) throw codes while under warranty? This is a question you need to ask the dealer who initially addressed the problem. The answer may be buried in the report prepared by the tech who worked on your car. The tech report is often times very comprehensive and different from the report handed to you when you pick up your car.
If it threw codes and the dealer merely reset the codes and sent you on your way, then you have, in my opinion, a strong case.