Over heating at high speed only

Hi - Dave here, contributing to RepairPal and providing expert advice since 2010. High temperatures when you have what would seem like plenty of air flow getting into the engine would seem to be caused by either a partially closed thermostat that is stuck in one position, restricted air flow in front of the radiator and fans (such as debris or some kind of object); a flow restriction in the cooling system (have you had the cooling system flushed?) or possibly some kind of engine issue causing coolant to get into the combustion chamber. I'd start with coolant flow, air flow and thermostat inspection first and then recheck. The other thing is - is the gauge the only way you are measuring temperature? It is possible that you have a gauge or sending unit issue - and maybe the temperature is fine. Seek guidance at a shop near you! https://repairpal.com/auto-repair-near-me Click the link to find some shops near you who can help out!