Rough Idle

After turning on my car and driving 100 feet i started to get a very rough idle fluctuating between 400-1000rpm. The car felt like it was about to stall every time it dropped so i shut the car off and turned it back on(problem went away). I'm guessing it has to do with the idle control valve.

Fault code: "CDBE Idling speed control valve CAN message bank 2"

I read on a different post that cleaning the valve and replacing hoses should be the solution. If anyone has different information pm me or reply below. If i have to replace the valve, which valve is recommended. There is OEM (400$) and the Standard motor idle valve (210$).

Car is 2011 m3 with 21k miles.

Did you just fill the tank recently?

msan wrote

Did you just fill the tank recently?

no it is 1/2 tank, i only use mobil/chevron gas so that shouldnt be a problem. I just checked the wiring and it all looks good didn't see any damage.

opihi5 wrote

After turning on my car and driving 100 feet i started to get a very rough idle fluctuating between 400-1000rpm. The car felt like it was about to stall every time it dropped so i shut the car off and turned it back on(problem went away). I'm guessing it has to do with the idle control valve.

Fault code: "CDBE Idling speed control valve CAN message bank 2"

I read on a different post that cleaning the valve and replacing hoses should be the solution. If anyone has different information pm me or reply below. If i have to replace the valve, which valve is recommended. There is OEM (400$) and the Standard motor idle valve (210$).

Car is 2011 m3 with 21k miles.

Don't buy anything yet! This may be covered under a BMW warranty extension specifically for this part "IDLE CONTROL DEVICE" BMW Part # 13417838024 under BMW SI B010316. Check out this thread for details first.

Theodore wrote

Don't buy anything yet! This may be covered under a BMW warranty extension specifically for this part "IDLE CONTROL DEVICE" BMW Part # 13417838024 under BMW SI B010316. Check out this thread for details first.

Sorry if this is not obvious but does this mean that all the issues with the gears being stripped in the throttle actuators are now covered in this extension?

I had a slight rough idle that I lived with for a year. The RPM's dipped ~50 intermittently and the car would shake a little. A couple of weeks ago, she went into limp mode. Ended up being my Vacuum break booster, she finally gave up the ghost. Idle is smooth as butter now, rock solid, no fluctuations.

msan wrote

Did you just fill the tank recently?

I have this issue right after I fill my tank. Luckily, my car is still under warranty right now. My car is at BMW right now to get this looked at yet again. Any idea what it is?

First time I brought it in they said it was an anomaly.

Second time it finally died and they replaced the idle control valve.

Now it's in and going to get checked Monday.

vlt wrote

I have this issue right after I fill my tank. Luckily, my car is still under warranty right now. My car is at BMW right now to get this looked at yet again. Any idea what it is?

First time I brought it in they said it was an anomaly.

Second time it finally died and they replaced the idle control valve.

Now it's in and going to get checked Monday.

If your rough idle only occurs shortly after fill-ups, on E9X M3s it's most likely the "Fuel Tank Breather Valve" BMW part # 13907838281 (see a picture here at ECS). Your dealership may not know this and could end up wasting your time replacing a bunch of components that are not the actual problem. Check out this thread for details.

Logodude wrote

Sorry if this is not obvious but does this mean that all the issues with the gears being stripped in the throttle actuators are now covered in this extension?

Wouldn't that be nice? The answer is no unfortunately, this warranty extension is for a different part then the throttle actuators.

Theodore wrote

If your rough idle only occurs shortly after fill-ups, on E9X M3s it's most likely the "Fuel Tank Breather Valve" BMW part # 13907838281 (see a picture here at ECS). Your dealership may not know this and could end up wasting your time replacing a bunch of components that are not the actual problem. Check out this thread for details.

Thanks for this info!

Theodore wrote

Don't buy anything yet! This may be covered under a BMW warranty extension specifically for this part "IDLE CONTROL DEVICE" BMW Part # 13417838024 under BMW SI B010316. Check out this thread for details first.

So would i have to drop my car off at the dealer, haven't had the problem again. I try to avoid dealers because putting on my cats and re-tuning ecu is a pita.

opihi5 wrote

So would i have to drop my car off at the dealer, haven't had the problem again. I try to avoid dealers because putting on my cats and re-tuning ecu is a pita.

Yes, unfortunately. Wait until you get the codes again though and maybe they will fix it in only one visit. The warranty was extended to 10 years/120,000 miles so you have time.

Theodore wrote

Yes, unfortunately. Wait until you get the codes again though and maybe they will fix it in only one visit. The warranty was extended to 10 years/120,000 miles so you have time.

Well at least I know I won't have to spend money on it. A cold start delete got rid of the problem for now.