So we made a run from West Yellowstone, MT to Rigby, ID(200ish mile round trip) like we have done several times this winter, but the truck was having random overheating spikes. Going up a hill, I can understand it getting a little warm. But on the flats and cruising at 65 while it's freaking 8 outside is absurd. It got to 219 the first time and then the fan engaged and it dropped the temp like a stone. On the way back, it got to 230 and that's when the fan finally came on. Again, finally it came back down really fast. Several times during this trip it would just start climbing in temp for no reason, stay at 197-199, then drop back down to 177 and stay there for a bunch more miles. Would the thermostats failing cause this?