Rpm goes crazy

[zman]

This morning when I pulled into a parking lot right before I turned off the car I noticed the car rpm goes wild. The car was on idle. The rpm went from 600 to 1500 and back again to 600. I did this for at least 20 times. It seems trying to keep the engine running or something. After that, the engine went idle smooth again like nothing ever happened.

I have seen this more than once but it has never been this bad. Most of the time, it goes from 600 to 900. And, it happens when I stop at the traffic lights.

Any thoughts?

 

[William330]

Could be the cold weather?

 

[jonaphn]

the only time i've enountered that was on my sister's old car..

the MAPS sensor died so the engine didn't know how much fuel to put into the cylinders. it would put too much fuel in and then burn it all at once causing the RPMs to go crazy.

i don't know if this can be applied to BMWs, but something similar could be happening to your car.