should be a clear sign that you're having sensor/electrical/gauge issues. If your radiator isn't hot, you're not boiling over, there's no smoke, etc, then it has to be your sensor, sender, or gauge. I've had this issue on my talon where I thought I was overheating, and it was the gauge cluster that was goofed. Same with my 240sx. Temp jumped up, but the car was cool. Changed the sensor/sender, etc....good to go.