Yes, if the head gasket is bad, it can cause the symptoms described.
When the head gasket is bad, compresison leaks and this would cause erratic idling but if you have coclant losses, it would also cause the same symptoms.
When repairs are carried out on the cooling system, bleeding must be done to purge out the air in system failing which the Fast Idle Thermovalve ( FITV ) and Idle Air Control ( IAC ) valve would not work correctly and cause surging.
Get a pressure test to determine if the head gasket is bad.
Saturday, March 6th, 2010 AT 7:15 AM