I'm Steve, my wife's name is Theresa and we own a 2007 G6. It now has app. 91,000 miles on it and it's been a going machine. I came across this website while looking for some info on a problem that has just cropped up with the G6. It seems that the temp gauge is not registering and the engine light is on. The electrical fan comes on at start-up but even after 40 minutes at freeway speeds, the engine is not overheated. Is this a thermostat prob or is there a sensor? The water pump was replaced last year but even then overheating was never a problem. Any help out there with this - and location of sensor/thermostat? I'd appreciate it. Thanks.