Overheating at idle

Does your fan clutch "roar" at startup? Once warmed up I would park the truck and verify the fan clutch is really pulling air.

I had this exact same problem on my Land Cruiser, which is somewhat common. You can actually open up the fan clutch and drain out the silicone oil, then replace it with heavier stuff (RC truck differential oil). It made a world of difference, cheap and easy to do. I would personally verify the fan clutch is working before messing around with an electric fan.

 

@Tundyfundy mine acted exactly the same was a pinhole leak in the radiator. Replaced radiator, hoses and thermostat and runs like a champ.

 

I had one time where the impeller slipped on the shaft of the water pump. You wont know unless you remove the pump. Hope this helps.

 

Just a little fix I have done recently and it worked for me, try adding a cooling fan to the front of your ac cooler, I wired mine up to a switch in the truck and I turn it on when I’m idling or in slow traffic and I have no overheating issues, the ac blows cold for a lot longer now to.

 

Interesting. I must experiment.