So a couple weeks back i was having an out of the blue overheating problem. When this was occurring my heat would go in and out, sometimes cold sometimes hot. So i figured it was the thermostat. Changed that, and it ran fine for a couple hours and is now giving me the same problem. There is no leakage under the car, no hole in the radiator. I was thinking it could be the water pump but i am really unsure.

Any thoughts or suggestions?

Thanks

 

you can get an idea about the condition of the pump if the truck is operating temp squeeze the top radiator hose and let go you feel a surge. No2 you could have a air bubble in the system turn your heater on and jack the front of the truck up so the front of the radiator is higher than all the hoses and run it till the termosate opens and start adding fluid. or maybe BHG? but i would'nt think it would run for hours before it over heats

 

Sounds like you may have an air bubble stuck in the system. The problem is figuring out why.

Are you loosing coolant at all?

 

There is no leak of coolant anywhere but it seems as if my overflow coolant container is always empty even if i fill it up right before I take it out and it overheats.

 

whelp- you're losing coolant somewhere, I might venture to say.