Why does my 2002 Ford Explorer overheating?

Answer 1

It might be your thermostat is stuck, radiator plugged, low coolant, leak, failed water pump, water pump fins have corroded away (happens when you don't change the coolant often or when you use water from a hose) or even something as simple as the radiator cap. Your best bet is check for an obvious leak first, in my experience I've found there bad about leaking from the lower thermostat housing. Pressure test cooling system and radiator cap. The water pump is a bit hard to diagnose but if you put a voltmeter lead one to ground and the other inside where the coolant is and if you see a reading above .5volts DC the coolant is too corrosive and should be flushed out and replaced. If your not to car savvy take it to your trusted local ASE certified master tech and let him diagnose and fix the overheating issue.