Car keeps over heating help Options

[Oreo20]

Both fans work.
Car warms up to normal quickly 5 mins top.
Water pump and thermostat swapped 15k miles ago

bad things I’ve noticed
Dirty radiator almost brown liquid due to oxidation original radiator I believe
And been working in really dirty environments radiator has bugs, dirt, feathers on fins

What would y’all suggest to fix this.?

Car only over heats when it’s super hot and on the highway with AC on
Goes back to normal if I turn of ac

Car stays in normal temp in city with AC on or on idle for long period time

[slavie]

Based on the symptoms, I would say the radiator sure isn't helping the situation. Keep in mind that the radiator has the smallest passages in the system, and it effectively acts as a filter trapping any debris and crumbs, reducing it's efficiency over time.

As for the fins, are you sure you're talking about the radiator and not the AC condenser? AC condenser sits in front of the radiator. Messed up fins and blocked passages would also reduce the system efficiency, blocking airflow to the radiator. They do sell rad fin straightening tools, so might be worthwhile to clean things the best you can and straighten fins out.

Finally, the coolant itself. Was it changed when the thermostat was replaced? It doesn't last forever, either. Toyota says 6y I believe, I'd say 10 years is tops for the coolant.

If I were you, I'd throw new rad on it and flush the coolant with Toyota Red (1 gal of concentrate + 1 gal of distilled water is what you need). The plastic tops on the rads crack with time, so rad is almost a maintenance item on these chassis.