I have a 2001 Sport trac and it has been overheating. Today I lost about 90% of power going up a hill until it died completely. Would restart once cooled off.
I do not have any CATS on the truck and the thermostat is opening in boiling water. Any other ideas ? I have plenty of water in the truck yet it is still over heating. I did notice the return hose from thermostat to radiator has no fluid in it and is soft.

 

Heat not working so I am thinking the water pump is not circulating the coolant. Thoughts?

 

Was not an uncommon problem for the water pump impeller to slip on the shaft. Only way to be sure is to remove water pump and check.