A fault with the idle control system would result in surging rpms while idling. It could be leaking vacuums, a faulty IAC, lack of coolant, clogged coolant to IAC.
If the Malfunction Indicator Light is showing, retrieve the trouble codes and let us know what it is.
Please consider a to help us answer more questions.
Thursday, October 25th, 2012 AT 3:54 PM