I have an old Chevy Cruze. 2010 Oct. LT variant. It developed an overheating problem in 2016, when I was turning on the A/C on mountain drive. I thought, nothing of it. It went fine. Then in 2020 It suddenly overheated, when I was not looking. I on the advise of a mechanic poured bottled mineral water into it one bottle after another, like 10 bottles. The Engine seized. I had the head changed. Then the water pump went bad, changed that . Then, the Oil pump went bad, changed that. When the oil pump light came up, there was not a over heating problem, though. Now, I had the radiator fixed, water pump fixed again, there is no Thermostat valve in Cruze LT.Again, it overheats at speeds over 40km/hr. This is driving me insane. I have spent 2000USD on this, to no end result. What remains to be checked?