Running Hot at Highway Speeds with A/C On

[Rusty Nail]

Just had another member with overheating issues.at road speed, aluminum radiator dual electric fans etc. The fix was a factory fan shroud,heavy duty fan clutch and 7 blade fan. Search engine wind tunnel fanshroud will lead you to the right thread. So obviously more air flow is needed at road speed than what comes through the radiator on its own. I'm with @fast 99 check the fan clutch. Easy check with a rolled up piece of cardboard. Remember with A/C on you are having to cool the condenser also,many vehicles have an electric fan that just comes on when the A/C is on for that reason.

Dontcha think it's cool sometimes the more that ppl mess with their trucks,the further it gets from stock, the more trouble they have?
Just goes to show ya- just because they can work a screwdriver, it doesn't mean they should.
There oughta have a school that would teach people how to work on cars and trucks.

 

[74Blaze]

Just goes to show ya- just because they can work a screwdriver, it doesn't mean they should.

Ain't much left that's stock in old girl. She usually runs OK. The challenge of these things is modifying them to learn from your mistakes.

 

[Knuck55]

Guess I could see that if the clutch was not allowing the fan to free flow enough air. Always learning.

 

[Rusty Nail]

Well,

In order to do that, you'll need to loosen (or remove) the belts first. Inspect. Five cracks per square inch warrants replacement!

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You'll need to give the fan a big spin - like The Price is Right. It should spin kind of freely , at least making a complete rotation?? Almost.
THe fan clutch has viscous oil in it and it is meant to have some drag and not spin TOO easy. Look at the coil on the fan center. If it has leaked, it will be covered in road grime stick in the oil there.

Spins a little but not too much.
Not covered in dirt and oil.

You can "feel" the oil in it while you spin. No big deal. If it has leaked out the clutch will resist your advances and be hard to turn on.
Replacement involves removing the fan shroud and an open end 3/8 or 10mm for the four nuts on the water pump studs.

Hope this helps!