Engine Overheating

[huggyjd]

My son has a 98 Ranger with a 3.0 V6. It started overheating so I replaced the thermostat and pressure washed the outside of the radiator to remove debris. As I added coolant , the water pump seemed to suck it through when the thermostat opened up .Still ,the temp goes to the red in about 15 minutes of driving. What should I do? Thanks

 

[Wicked_Sludge]

likely causes are a clogged cooling system, blown head gasket, inoperative fan clutch, worn water pump.

does it overheat driving down the highway? or only at low speeds?