Running warm at idle

[Khaley71]

I’m having an issue with my 05 Ram 1500 with 5.7 running warm at idle. I replaced my radiator about 3 months ago due to it leaking. The leak was the plastic tank separating from the aluminum. There were no overheating issues or any other problems, just the leak. I installed a new radiator and new thermostat. About two weeks ago I had to replace the water pump as it started to leak. The leak wasn’t from the weep hole in the pump it was from the gasket/machined mating surface. After replacing the water pump and the thermostat again(just because I had it apart). I also installed a new fan clutch as the OE had almost no resistance when I spun it and looked like it had been leaking oil possibly? Now at an idle my Ram doesn’t really overheat but the gauge does rise slightly past they half way point. It goes down to normal when I take off. The heater will run you out of the truck and seems to operate normally. I have also noticed with out the radiator cap on there’s almost no circulation in the radiator. I was thinking maybe the new radiator might have blocked tubes? possibly air bound? When I drained the system for the repairs the old coolant looked good other than a little discolored. Idk what else to do and figured I’d ask before pulling the new radiator to replace it, just don’t want to throw parts at it. Also I have serviced/flushed the system in the past.

 

[Karlsweg]

Probably the fan clutch.

 

[CorDog009]

Usually if the fan clutch fails, it locks up and is continuously spinning.

 

[Wulf]

There is not often an air block in the radiator itself that I have been aware of, but there can be elsewhere in the coolant system sometimes. Either in the hoses or the block itself from what few times I have personally experienced this. One way I have heard of testing this is to get the engine up to operating temp, and then squeeze, *carefully*, the lower rad hose and see if it is getting pressure or not.

If it is the fan clutch like Karl and Cor said, the fan always spinning is not necessarily a bad thing. Just not sure if that is the case, if it would cause it to run hot like it is. You can get the radiator/coolant system pressure tested, and I think that might be enough to force the air out of the system, if there is any air where there shouldn't be.