When you do your flush and change the thermostat, put in some water wetter with the new coolant, the contours run at a fine temperature while driving down the street, but if you sit at like a stop light, or busy intersection for to long they heat up. So Water Wetter will help keep the temp down. I had the same problem, the temp wouldnt go down on its down. But if I ran the AC or heat on the lowest setting, the temp went right back in the middle to where it should be. But I didnt want to run the AC when I didnt need to as it would burn gas more and kill power. So I decided to do the thermostat, and it stays pretty cool by itself as long as I keep the car moving.
