Rough Idle

[kwike92]

hey guys so you know when you turn your car on from a cold start how the engine idles rough while its in open loop? and then after maybe a couple mins the idle drops down to under 1k? Well today i turned my car on and i wouldn't say it was necessarily "cold" because 4 hours prior i finished driving it 50 miles. but any how, when it fired up, the idle was rough, as usual since it was kinda "cold" well i thought id give it a little gas and bring the idle to 2k to just get it warmed up faster before i took off, well when i did it almost sounded like i has an exhaust leak. it sounded terrible. Then when i let off the gas the idle dropped to under 1k and it began to surge as if it wanted to die. After about 10 seconds of it surging it went to normal.

i drove it on the freeway, did a couple hard pulls, no lack of power, no check engine lights, no nothing...

sorry for the long story here, but is this something i should be concerned about????

[m3an]

no, if it ain't broke don't fix it. Too many people concerned about everything ruins the fun. Wait until it stops running, then fix it.

[M3Denver]

Originally Posted by kwike92

hey guys so you know when you turn your car on from a cold start how the engine idles rough while its in open loop? and then after maybe a couple mins the idle drops down to under 1k? Well today i turned my car on and i wouldn't say it was necessarily "cold" because 4 hours prior i finished driving it 50 miles. but any how, when it fired up, the idle was rough, as usual since it was kinda "cold" well i thought id give it a little gas and bring the idle to 2k to just get it warmed up faster before i took off, well when i did it almost sounded like i has an exhaust leak. it sounded terrible. Then when i let off the gas the idle dropped to under 1k and it began to surge as if it wanted to die. After about 10 seconds of it surging it went to normal.

i drove it on the freeway, did a couple hard pulls, no lack of power, no check engine lights, no nothing...

sorry for the long story here, but is this something i should be concerned about????

No big deal fairly common with the m3 to have noises when cold or cool.

What year is your car ?

Also idle fluctuations can be caused by a bunch if stuff ie: cooling fans coming on or a large draw on power. Happens in most cars, get your battery and alternator checked Just in case

[kwike92]

I see... Yeah the car runs fine.

My car is an 09 with 19k miles. I'll put a volt meter to the car and just see what it's charging at.

Anyway, thanks for the help.

[Draper]

I was seeing the exact same behavior a few days ago. I dropped it off at the dealer and they found a code for some solenoid which they said would cause a rough idle.

They swapped it out and it's been running great ever since.

[kwike92]

Originally Posted by jzbm3

I was seeing the exact same behavior a few days ago. I dropped it off at the dealer and they found a code for some solenoid which they said would cause a rough idle.

They swapped it out and it's been running great ever since.

Oh ok cool. I was hoping I wasn't the only one. I guess it won't hurt to drop it off at the dealer to see what they say.

Thanks for lookin out !