My dodge truck is running hot up around 220 when driving in town, over the Mt. Pass etc.
I've replaced the thermostat with a 190 and it still is running hot, my truck is a 2001 with
215000 miles, it's been bullet proof! I had the original Thermostat replaced at a garage
about 205000 miles because the OEM stuck open and the truck would not run up to
operating temp. He also flushed and filled it with new coolant.
My guess, GUESS now, is that the coolant mixture is off. Most people don't know this, but its the water that does all the cooling work, not the antifreeze. The antifreeze is simply a liquid that is manufactured to attempt to cool as good as water but prevent from freezing during winter hence the name. Water is the best cooling, but it will seize the block if it freezes. Several tests decades ago determined the optimized mix is 50/50. Too much antifreeze and the vehicle gets hot, too little and not enough protection. SO I recommend thinning out your mixture with more water.
May be time for a new radiator,
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