Just recently I noticed that my temp gauge creeps over the half-point mark and slowly, but surely, increases. It does it more often if I am shifted to park or stopped at a red light. The needle on the gauge never hits "the red", but it has gotten pretty close a couple of times. I will be the first to admit, I am nowhere near a car buff, nor do I have the expertise as many writers on this site. Radiator looks full and so does the reserve (original GM DEX Coolant and early this summer added a little more DEX to the reserve). At every oil change they check it and they say its fine. To my knowledge I do not think the vehicle has ever had a flush or previous problem with the radiator (no major heating/cooling/power-train/engine/accident has ever been reported via my paid "Car-Fax" report). Unfortunately, because of my ignorance toward more complex and operational technicalities with automobiles, I am not too sure where to begin, or what may even be the problem. Anyone with any insight would be greatly appreciated!