idle drops and cold start revs fluctuating

[E90M3velocity]

I just noticed this at the beginning of this week, my cold start revs fluctuate as it will bounce up and down in a slow manner and once fully warm up the idle will drop to 500 rpm. When i press on the clutch it will go back up to normal. The car is approaching 62k and the only recent thing i did to it was changed the battery and coded it. Any advice on narrowing down on whats causing it will be greatly appreciated before i hand the keys to my only car to my indie shop and have them spend a couple days diagnosing it.

[Gsv77]

Originally Posted by E90M3velocity

I just noticed this at the beginning of this week, my cold start revs fluctuate as it will bounce up and down in a slow manner and once fully warm up the idle will drop to 500 rpm. When i press on the clutch it will go back up to normal. The car is approaching 62k and the only recent thing i did to it was changed the battery and coded it. Any advice on narrowing down on whats causing it will be greatly appreciated before i hand the keys to my only car to my indie shop and have them spend a couple days diagnosing it.

I had an 08 that did that, now have a 12 with 9k miles that did it too, started stalling when cold a day or two ago, idle actuator being replaced under warranty and car will be back tomorrow.

[IMG]

Sounds like an ICV issue.

[L4ces]

Originally Posted by Gsv77

I had an 08 that did that, now have a 12 with 9k miles that did it too, started stalling when cold a day or two ago, idle actuator being replaced under warranty and car will be back tomorrow.

Keep us posted.

[E90M3velocity]

Originally Posted by L4ces

Keep us posted.

I suspected the icv since i read that is a common problem part on these cars, but i didnt want to jump ahead of myself. Keep us posted if it was the icv.

[thekurgan]

Originally Posted by E90M3velocity

I suspected the icv since i read that is a common problem part on these cars, but i didnt want to jump ahead of myself. Keep us posted if it was the icv.

Try some techron concentrate first if you're out of warranty or want to try something on your own. Bad gas can cause this; I've had it twice from the same filling station before it changed ownership.

My car was like this:

Techron concentrate plus took care of it, it never returned.

[Jbook]

Anyone know how much the ICV replacement job usually costs? Not for my car.

[W Cole]

Originally Posted by thekurgan

Try some techron concentrate first if you're out of warranty or want to try something on your own. Bad gas can cause this; I've had it twice from the same filling station before it changed ownership.

My car was like this:

Techron concentrate plus took care of it, it never returned.

My car was having issues like this on start up even after replacing the ICV. Ended up being the coolant temperature sensor and/or the wiring harness. I think there is a service bulletin regarding the issue.

[E90M3velocity]

[QUOTE=thekurgan


Techron concentrate plus took care of it, it never returned.[/QUOTE]

Thanks ill look look into it, though my idle fluctuations are not as erratic as yours. Question, is that from a cold start? Mine doesnt hang around 1100 for long and settles down to 800 quickly in a normal bases. 2nd owner for this car, so i wished i knew how things came from the factory.

[thekurgan]

Originally Posted by E90M3velocity

Thanks ill look look into it, though my idle fluctuations are not as erratic as yours. Question, is that from a cold start? Mine doesnt hang around 1100 for long and settles down to 800 quickly in a normal bases. 2nd owner for this car, so i wished i knew how things came from the factory.

This video isn't my car, but my car had this issue at cold start, first thing in the morning. It was fine during the day, just after it sat overnight.

[thekurgan]

Originally Posted by W Cole

My car was having issues like this on start up even after replacing the ICV. Ended up being the coolant temperature sensor and/or the wiring harness. I think there is a service bulletin regarding the issue.

This actually makes a lot of sense, especially sitting overnight.

[E90M3velocity]

Well i just started the car and "check engine" light flashed for a moment until the dsc light came on. I had the multiple lights and dsc error light with the "reduced power" earlier this year and it stopped and therefore i didnt bother with it. Could these symptoms be a bad icv, bad throttle actuators, or simply bad spark plugs.

[L4ces]

You can take it pep boys for a free scan to get the codes. Mine did the same until I replace the low pressure fuel rail sensor.

[E90M3velocity]

Originally Posted by L4ces

You can take it pep boys for a free scan to get the codes. Mine did the same until I replace the low pressure fuel rail sensor.

I got that replaced a little under a year ago, when it started to reduce power and pull multiple codes around spring time i first thought it was the throttle actuators but it all of sudden it stopped and went away. Im thinking it could be the icv now that the idle is acting up. The transmission is whirring a little more louder and i dont get it only idles normal only when the clutch is pressed.

[L4ces]

Originally Posted by E90M3velocity

I got that replaced a little under a year ago, when it started to reduce power and pull multiple codes around spring time i first thought it was the throttle actuators but it all of sudden it stopped and went away. Im thinking it could be the icv now that the idle is acting up. The transmission is whirring a little more louder and i dont get it only idles normal only when the clutch is pressed.

Wish I could offer some insight.

For what it's worth, I am at 80K and only changed the low pressure fuel rail sensor.

[bde]

Originally Posted by W Cole

My car was having issues like this on start up even after replacing the ICV. Ended up being the coolant temperature sensor and/or the wiring harness. I think there is a service bulletin regarding the issue.

Do you know the SIB number by chance?

Thanks!