Having a strange problem with the cooling system on my 94.5 7.3L. This is a project truck... gets started up every once in a while, but hasn't made any real long drives in the last couple of years... mostly just around town. On short drives, my temps stay low - but on a recent dump run, temps started to creep up towards "L" on the gauge and I quickly turned it off to let the truck cool off. Last year this truck had a leak from the water pump, so that was replaced along with the up pipe. When i opened the hood after running hot, i noticed the upper radiator hose was kind of hot, the lower radiator hose was kind of hot, the water pump area was hot, but the radiator was ice cold. Opened the radiator cap and the coolant in the radiator was cold. The only warm area of the radiator was where it meets the upper radiator hose. The coolant system had pressure this whole time, coolant is clean and green, and there are no coolant leaks from the truck.

At first i thought i had air in the system, and i was able to purge out so bubbles by squeezing the radiator hose... but this hasn't solved the problem. I'm leaning towards the radiator being clogged up... but could it be that the new water pump that was installed is faulty? Any advice would be appreciated, and a picture of my truck is below.

 

Its possible that the radiator is clogged. Try running it with the the cap off for awhile to get air out. When I put a dieselsite coolant filter on it was amazing how much junk the filter caught.

 

Thanks - there is definitely a lot of crud floating around in the system... a filter is a good idea. I was under the impression that the guy that replaced my water pump for me would have bled the cooling system already... but that is probably the cheapest place to start troubleshooting.

 

Normally they don't need bleed out, pour it in and go.

 

Can confirm, I didn't bleed my system when I flushed, I don't recall seeing air bubbles or anything abnormal needing attention.

 

My truck has the powerstroke with the IDI cooling system. Not sure if that makes any differences in needing to bleed. There were definitely some air bubbles in there when i first burped the system squeezing the upper radiator hose.

 

Is the coolant moving when the truck is running? Obviously, only check on a cooled engine. Thinking maybe the thermostat isn't working properly. Coolant not circulating would cause what you're saying. The hoses would heat up from the engine but leave the radiator cold as the warm fluid isn't moving through it.

just an idea.