'97 Cherokee sport 324k miles. Head gasket? Thermostat stuck open? Or water pump? Normally runs 210 or right below. Turned it off and started pouring rusty water out from over flow then shot temp up to red line. I've had the jeep a year, haven't changed the t-stat or water pump. Radiator was replaced last year along with rad cap.

 

Even though rad caps some what new sounds like its not holding pressure. Getting a system flush and checking cap and cooling fans for operation would be a good place to start.

 

If the coolant is red and muddy, it's probably time for a cooling system overhaul: flush, radiator, hoses, water pump, thermostat, radiator cap. You might want to go ahead and replace the fan clutch while you're at it, since it's a lot easier to swap out when the radiator is out of the way.

 

definitely check your fan clutch and auxiliary fan, they make a world of a difference in cooling the engine.