High Temp when in idle

[Richard Wilks Jr]

I notice that my truck (a 99 GMC 2500 w/ a 7.4l 454) runs at almost 210,a little over, when I idle for long period or I am parking my 5th wheel. Once I give some gas and get going I hear the fan (I call it the jet engine). I do not hear the fan in idle. Is there anything wrong? I'm thinking clutch fan or relay is not working. 

Edited June 6, 2021 by Richard Wilks Jr
Forgot truck type

[CamGTP]

With what you said, that to me says nothing is wrong.

 

Seeing 210 on the temp gauge is not considered hot by any means, you'd only be real concerned if you where seeing 225-230+ on a normal basis.

 

The fan is still moving at idle right? Is the fan shroud in good shape too?

 

When was the last time you cleaned the fins on the radiator with a hose or compressed air?

 

You could also test the thermostat and or just replace it for good measure if you've got no real clue how old it is. Then bleed the cooling system and see what it's like.

[Richard Wilks Jr]

Thanks. I will check fan in idle. Shroud is still in good shape and blades are clean. 

[Brian Lindsey]

if you're going to pull a fifth wheel maybe electric fans should be in your future, saves gas (i know a 454 will pass anything but a gas station)and runs cooler.

[CamGTP]

A proper working clutch fan will out cool a set of electric fans. This is why semi trucks and even smaller chassis trucks still all run clutch fans.

 

The electric fans have the advantage of letting you set the temp they come on at. But a clutch fan puts out some serious air movement when they come on full blast.

[J F]

210 is not hot. You have a T stat set to start opening at 195. So why would 210 be hot?

 

The early TBI set ups ran normal temps of 195 - 240. 240 being long grade pulls. The clutch fan should begin engaging at around 150-190 or so radiator discharge air temp. Not coolant temp.