Today about an hour ago my coolant light came on. As soon as I get home, I immediately check the dipstick, the fluid was up to where it says hot(So obviously it isn't low). So maybe my coolant sensor has failed on me or do you think it would be wise just to buy a new sensor and flush out the coolant and put new coolant in. Also I have a relative that has a Montana Van made by Pontiac that has put dexcool in his reservior, it's a the orange color. Do you think it would be safe to add that to my car or is it stricly green because when I read the manual that came with the car, it says the cooling system in my vehicle is filled with new dex-cool (orange-colored, silicate-free) engine.

 

Some people dont like the dexcool stuff.
Your sensors dirty or gone bad. You can try cleaning or just buy a new one for 50$.

- Drain the radiator about 1/3rd. '(Plugs underneat on the passenger side)
- Remove the retaining clip off the old sensor (Take the battery out, its the square sensor connected to the radiator.)
- Pull the coolant sensor out.
- Put new Sensor in. (or clean the metal rod in the old sensor and see if it works).

Should be a snap.

 

Here's a few pictures that might help.
http://www.pharmacy.arizona.edu/staf...antsensor.html

From what I've read you keep the coolant the same. Add orange to orange or green to green. You can change from orange to green but flush the system first.