So here the deal with my cars problem. I replaced the following below
-Water pump
-Temp sending unit (Napa)
-Thermostat
-Flushed the system
-Pulled radiator and had it rodded out and cleaned

This all still did not fix the problem. I then took it to Pontiac and they tested everything. The temp test they did said the car was running at normal temp. (180-185). So it was either the gauge or the temp sending unit. they also said that I needed to buy a Pontiac sending unit and that the ones after market are junk. So I bought the sending unit, put it in and it has been fine every since. Crazy!!!

Good luck to the reast of you! I still think the Dexcool coolant is junk too!!!

Bronco Sport