Getting hot on the highway with the AC on.
Just an obvious FYI. A properly working "cooling system" Like the cars A/C does NOT cool the engine , it removes the heat. it "radiates/removes" the heat from the coolant. That is one of the main reasons that radiators normally have a Black paint applied. Since black absorbs heat it also radiates heat. Think SR-71 Black bird.
A marginally working cooling system will be overwhelmed by the condensers heat transfer while the a/c is operating.
