OK so I felt that this was kind of odd and wanted to see if any of you guys experienced this. Ive have my car for bout 5 months now has 9k on it only happens if the car has been warned up.Sometimes i will start the car and right as the car starts the rpm would drop a lilttle past the regular idle and then it would normalize itself to its regular idle right below 1k.Is any else getting this?

 

not quite understanding your post but i think mine does soething like this.

auto or 6mt

 

ok maybe i didn't elaborate clearly. I am 6mt. When you push the start button normally the rpm will go up and back down to normal idle point..but sometimes as the needle start going down to the normal idle it will dip and go below the normal idle and go back to normal idling rev.

 

Sounds weird that its constantly moving. It should idle around ~1200rpms for a good 10-15 secs them slowly idle down to 1000 and then to normal idle rpm of about 600. If its going below that mark, you might want to try an ECU reset. Do you drive your car daily? Is there any chance there is water (moisture) in your gas tank?

https://www.myg37.com/forums/d-i-y-installations-modifications/175792-easy-way-to-reset-ecu-without-battery-disconnect.html

 

its not constantly movin only happens on warm starts when the engine is warmed up already for instance I would shut the car off and turn it back on 5 mins later.it only goes below 600 rpm when u first start the car the needle will dip then go bac to normal idle.

 

I understand your post, its only happening on a cold start but still, it should not fluctuate below idle RPMs.

 

I suspect this is normal. When the engine is shut down and the coolant is no longer circulating the engine will heat up higher than normal operating temperature (heat soak). When you restart the car the temperature sensors read those elevated values and ECM raises idle speed to increase cooling.

 

mine was doing something similar and i reset the ECU and now its good..

 

maybe it's the AC compressor kicking in.