HELP 2005 5.7 Overheating at idle

[Johnbrown8907]

Truck overheats at idle. I noticed it while going down the road a couple days ago. I thought it was the thermostat so I changed it. Got in it today for the first time since then and it’s still doing it. Is it the fan clutch? The heater temp is also fluctuating with the engine temp. I’ve read about doing an electric conversion for better performance. If it is the fan clutch could I go with that route?

 

[Recoil]

How many miles are on the engine? When is the last time the cooling system was flushed and/or the water pump replaced?

 

[Wallyb4]

Do you have the fan shroud on it ? You should feel some resistance on the fan clutch if you turn the fan. IF not replace the fan clutch.

 

[Karlsweg]

Fan clutch. With it idling take a rolled up news paper and safely try to stop the fan with it. If it stops the fan from spinning the fan clutch is bad.

 

[Karlsweg]

And never to be heard from again! OP other people like to hear the fix!

 

[brental1]

Check the AC condenser fan (electric). There's a hack to cut an inch out of the shroud so you don't have to remove the AC lines.

 

[Khaley71]

Air in the system maybe.

 

[5times_the_charm]

I’m guessing fan clutch which I would replace the water pump the tensioner pulley the idler pulley and serpentine belt or possibly need to burp the coolant. At least be sure to check all the parts I mentioned cause the fan clutch seams to go and takes the water pump with it or Visa versa and the belt tensioner can be the cause and sense I usually lump those 3 together I throw in the idler pulley and belt with it just for piece of mind