For almost 2 months I notice that my fan clutch will not freely. If you turn off it not that easy to turn.

But my cousin had 94 Fsuperduty 7.3L IDI and friend had 97 Fsuperduty powerstroke 7.3L I watch fan spin so slow that you could count fin at idle. When you turn off it would stay spin for about 10-20 seconds.

On mine it doesn't do that. It just stay spin HARD and you turn off it stop quick. That why I had cardboard on there since it get forever to warm up after 10 miles of highway.


New clutch I can't afford but found 2 fan clutchs from friend's junkyard. He want $25 each with blades. It came from 95 and 00 International T444E out 4900.

They look alike to me but not sure about blades size.

 

Mil, i have the EXACT same problem/symptom. 15minutes on freeway, and thats after 10-15min warming up in driveway, my temp needle has yet to budge. Once it does, then when i'm at idle, it'll go to "C" again. My fan stops when engine shuts off, has quite a bit of resistance when turning the blades, and never free spins at anytime...

I have a brand new OEM one, sit'n in a box, think i'll install it tomorrow, and re-post on this thread the outcome...

BTW, my buddy has an e99, and the fan spins freely when motor is off, also does not spin with same rpm speed as motor...

 

On your issues it sound you had bad thermostat. They shouldn't get cooler down after idle. Mine doesn't do that but I had new thermostat on it.

Get motorcraft thermostat from O'reily . Previous owner stick stant thermostat in there and I couldn't believe how long for heater to be HOT. New motorcraft thermostat now I keep heater on LOW or off.



On Fan clutch I agree on it. I wish it was electric one like 6.0L. Mine sound like airplane/squeak pitch.

 

Installed a new thermostat when i did the W/P and new upper/lower hoses, but it wasnt an OEM stat, in fact it was a NAPA one. Maybe ur right, probably be wise to exchange it out for a M/C one...

 

If the fan spins freely it is a sign of a bad fan clutch. Turn the shaft on a new fan clutch and you will feel quite a bit of resistance.

If it spins freely than it most likely is not locking up when it should. Lock up should happen when under hood temps around the fan clutch reach about 220°.

The 7.3 fan clutch is a viscuous coupling type with a heat sensitive bi-metallic lever which operates a valve that allows fluid transfer to engage lock up.

Some info from Wikipedia.

 

Payson, so your saying that, both me and Mil, have "working" fan clutches and that our friends have worn out/damaged ones? Man i hate pissing in the wind..($$$)

 

That's what I'm thinking.

Compare the fan shaft turning resistance of your new fan clutch to the one in your truck.

 

I don't think they supposed to do that.

I was test on mine cold start in 3oF it spin all times it hard spin. Later it 33oF sun day drive for 20 miles then I open hood to see fan. Turn off key it stop INSTANT. Not freely spin like I see on Gas vehicles I had.

 

If the gasser had an electrically controlled fan clutch that might not be a good comparison.

Like I posted earlier "Turn the shaft on a new fan clutch and you will feel quite a bit of resistance". I'm going by experience comparing "like for like".