Hi. I bought an '02 Blazer about 2 years ago. At that time it only had 68,000 miles. Now it has 84,000. Everything seemed fine for the first year. It was a great truck. Now all of a sudden everything seems to be going wrong all at once. My driver's side window no longer works, my back hatch will not open (no matter which button you push, key ring button, dash button, or hatch button), my key cannot come out of the ignition properly (I have to put a screwdriver in the emergency release button underneat the steering wheel shaft to release my key once in park), my heat just went out, and now my temperature keeps spiking when I drive anywhere more than 20 minutes away. I have to pull off the side of the road and wait 15 minutes before starting the engine up again. I changed the thermostat yesterday. It really needed to be changed (it was very rusted out), and I thought that would fix the problem, but I am still experiencing temperature problems. I guess my main question is what is the NORMAL running temperature for a Chevy Blazer? Below 210? Right at 210? I just want to fix the problem before I cause a much more expensive one, such as blowing a head gasket. Thanks for your time.