When engine is cold, the idling speed would be higher than normal and gradually decreases and should be stable after approximately 7 minutes.
If it is too high, the PCM ( engine Computer ) could be getting the wrong signal and increases the idling speed too high for extended periods.
Is the Check Engine Light indicating and have you tried to retrieve for trouble codes?
Check if coolant level is correct.
Thursday, January 6th, 2011 AT 2:24 PM