I have a 2001 explorer, it wont heat up anymore. I drive it for a half hour and it wont heat up, the needle is buried on cold on the gauge, the heater blows cold air, and it has water in it. I did use some stop leak a while back but that was weeks before this all started. Any ideas?

 

There problem

clean radiators to remove that stop leak. Or get to shop and they will flush it.

Then try change thermostat to 195oF.

 

can I flush it myself, and, how hard is it to change a thermostat on these newer motors. last time I changed one was on an 84 S-10 with a 2.8

 

stop leak is good for a hole in the radiator or gasket. one bad thing that can happen is to gum up the thermostat and it will not close all the way. the water pump will circulate water thru the radiator all the time and nver warm up. YOu need to pull the thermostat, clean it out real good, or install a new one. If you leak is now fixed with the stop leak, drain out the rest and refill with clean antifreeze and you should be o.k.