Hi it is not a problem however it is when the engine is cold the temperature being cold the engine needs to get up to a working temperature so the engine management system does this to get it warmed up quicker. normal behaviour for a car engine.

idle air control valve

Its the idle control valve.

Thanks, will look into this and see if that works and post my results..

My car idles high between 2000 and 2500 rpm when I drive 15 miles or more once I put the car into Neutral or Park. Idle go's back to normal if I restart the car. Any idea as to what may be causing the problem?