Rep Power: 298

Yesterday, driving around, I pulled into the gas station to get something to drink and left the car running. When I came out I noticed that my temp needle was on H. I started to drive and as soon as I did that it instantly went down to normal. I parked it again to see if it would, and nothing. It did again a second time later on. Also, sitting at a red light on the road, it doesnt go up or down. This happened once before about 4 weeks back, and when I went and opened up the hood and look at the radiator res tank, it was Full and some anti-freeze had pushed its way through the top cap as there was a bit on the engine bay. IT DID come from there, so no worries about a leak. It has been checked for already as well as if the fans are running. They do. What we did about 4 weeks ago was syphen some anti-freeze out of the res tank so it was back to its Min/Max level and then put a fair amount into the rad, (Seemed like it was empty) What could the problem be of this? I can still have A/C and heat when driving and it doesnt go up regardless of if I have these on. Could there be a blockage or thermostat problem somewhere? I would like to try and eliminate this problem myself. I have approximatley 140,000KM's on the car and have not had a rad flush yet. It will be done asap. Any CONSTRUCTIVE help would be greatly appreciated. Anything else, please dont bother. Thanks

 
Rep Power: 298

Anyone have any ideas?

 
Rep Power: 424

you can try changing the cap and the thermostat, check the fan switch, but more than likely, its a head gasket starting to go.