After blowing a T connector I started looking for "why". I dismissed the water pump (replaced last year). I did find the radiator was restricted. Cleaned and flushed it as well as h-core, changed hoses, thermostat and r-cap. But still running hotter than normal. After driving for about 45 minutes it got hot enough that I had to run heater to keep from overheating. Put sealer in fluid by chance there was a head gasket leak. Checked oil and fluids and did not find any evidence of a gasket leak. However, I did find that when the engine would get hot...that if I stopped, ran the heater, and increased engine rpms that the temp would come down.
?1. could I have a gasket leak and not notice it.
?2. based on the rpm mentioned above, could the w-pump need to be replaced (when I first start the engine I hear a squeek like a dry pulley).
?3. could the radiator still be plugged.
I would really appreciate some advice.
Best regards,

 

I would assume your water pump could have a broken propeller cause on my old truck if I gave it a load it would overheat but if I let the car run high enough the propeller pumped just enough fluid through to cool the engine. Mine was made of plastic and it melted away so I replace it with brass. Idk if yours would be that if it is squeking

 

If your Water pump was bad or going bad there a couple of things you could check. There is a weep hole under the neck connecting to your fan. If it seeps water there it is going out. Also if you disconnect the belts to the fan, you can check the fan pulley for play. There should be none. I had a 3.9 and I put a 180* tstat. A clogged or failing tstat can cause ovetheating also. Does your truck have a fan clutch? Check it for seepage or play. In regards to your squealing, Make sure your water pump belt is not cracked or ovetly tight. Too tight can lead to water pump failure also.

When you mentioned radiator being restricted, what exactly did you see or find? A radiator shop can clean and repair your radiator for like $75. Of course you can buy a new plastic/ aluminum one for $100. I put one of those on mine and its been keeping it cool for 3 years now. They are more disposable though than the originals.