It sounds as if you have air in the system. To temporarily fix the problem, let the car cool down. Take off the radiator cap and turn the car on. Put the heat on full blast out of the vents. Top off the coolant in the radiator and the overfill bottle. As the engine is running you will see air bubbles coming up throw the radiator cap. When the car is fully warmed up and there is no more air coming up through the radiator neck, put the cap on and drive.
Now for the long term: Something caused this (if this is indeed your problem). You will need to do a pressure test and check for leaks otherwise the problem will end up happenning again.
Edit: Or as SHOooo said, a sticky thermostat... I guess I overlooked the obvious and jumped right into the more complex. frown
<small>[ November 03, 2002, 11:57 PM: Message edited by: Mikeys_Taurus ]</small>
