advice needed for BMW veterans.

[kkttsang]

This is my first BMW so im not too familiar with it, if i can get some of you BMW veterans' advice that would be great.
The car is 2008 328i 28500km

So on cold start ups, the engine rpm shoots to around 1200 rpm then slowly drops to 600 rpm, like every other car, but when the rpm is dropping the rpm bounces and car shakes a little bit, once it gets to 600 rpm everything is fine, theres no rpm bounce or shake at 600 idle rpm. Theres no engine light or warning light. Car runs fine. The rpm bouces at start up only occurs occasionally. when it does happen it only happens breifly. I don't know if it's misfire or what, but is this normal, or should i bring it in?

Even though i have CPO if i bring it in and it is normal they gonna charge me 200$. Do anyone have a BT tool that can read 2008 328i error codes?

[Energy]

What you describe sounds normal to me. As your car warms up the revs drop slowly until it settles at idle.

[kkttsang]

Originally Posted by Energy

What you describe sounds normal to me. As your car warms up the revs drop slowly until it settles at idle.

thnx for your reply, what about the rpm bouncing while its warming up, is that normal too? or do you think it's misfires.

[?NR]

Check the mass airflow sensor and or throttle body.

[godwin]

Get the car scanned, if there is really a misfire it will show up at GT1 or something similar (they are common among enthusiasts). If you are really concerned leave the car at one of the BMW specialized shops eg Nixon etc.. let them test the car during different times of the day.

[pb.kidz]

Originally Posted by kkttsang

This is my first BMW so im not too familiar with it, if i can get some of you BMW veterans' advice that would be great.
The car is 2008 328i 28500km

So on cold start ups, the engine rpm shoots to around 1200 rpm then slowly drops to 600 rpm, like every other car, but when the rpm is dropping the rpm bounces and car shakes a little bit, once it gets to 600 rpm everything is fine, theres no rpm bounce or shake at 600 idle rpm. Theres no engine light or warning light. Car runs fine. The rpm bouces at start up only occurs occasionally. when it does happen it only happens breifly. I don't know if it's misfire or what, but is this normal, or should i bring it in?

Even though i have CPO if i bring it in and it is normal they gonna charge me 200$. Do anyone have a BT tool that can read 2008 328i error codes?

My car did that until the Vanos solenoid failed, and my car died in the middle of the road. If its a CPO and still under warranty they'll charge you like $50 deductible if they have to replace the solenoids.