Temp sensor reads hot for about a mile then goes down to normal. replaced thermo

You'll only know about the performance of the temperature sensor by checking the real temperature of the coolant using a temperature gun or similar, while simultaneously monitoring sensor output with a diagnostic tool. If you've made all those repairs, have you ensured the air has been purged from the cooling system? That can cause problems. www.repairpal.com/repair-shops Seek the guidance of a shop near you. Good luck.