Well I have a 1996 Pontiac Grand Prix SE coupe and the temperature gauge stays below 150 and it slowly rises after 15 minutes then it keeps going past 210 (which I've read is normal). Until I turn on the heater to full blast then it goes back down to 150 and it slowly rises. I haven't seen the other fan turn on ( the engine fan not the AC fan). I think the reason is because my auto teacher drilled a hole in my thermostat before I put it in. And I noticed a small leak of coolant somewhere under the engine in front of the oil pan. Point is what should I do to it? Or should I just leave it and find out where that leak is coming from?