Testing Fan Clutch?

Jeffncs

Jeffncs

Well-Known Member
Joined
Apr 4, 2017
Location
Wake Forest
2022 F250 with thw 7.3. Maybe 46,000 on it. Engine sounds really loud from dead stop and wondering if the fan clutch failed. Even my wife and son said something about the engine being really loud recently.

A failed fan clutch seems to be pretty common on these trucks but don’t want to assume because the part is a little pricey. I’m debating getting ford or local shop to repair it because I just don’t really have the time this week. May get them to replace an idler pulley thats showing some leaking oil while they’re under the hood too.

Is there any way to test the fan clutch? Doesn’t seem too difficult and will make the time if testing can confirm it and the quote comes back $$$.

Engine off - fan turns with some light resistance. No detectable wobble.

Engine on - fan always spinning. I’ve never seen it not spin which may be normal.

Appreciate the help
!
 
Thermostat fans normally spin about 30% of engine speed and ramp up from there based on the thermostat reading.

I agree with the above, just lock it on until you have time to replace. It’ll be a little loss of fuel economy
 
No codes in memory. Just sounds like a jet turbine from dead stop. MPG had been ~13 for as long as I can recall.

Sounds awful and sounds like I’m accelerating hard when just putting. Walkers in neighborhood always give me a dirty look because of it.
 
Jeffncs said:
Sounds awful and sounds like I’m accelerating hard when just putting. Walkers in neighborhood always give me a dirty look because of it.
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Oh, I get that part too! 6.0L with OG Powerstroke thermo-clutch adapted... sounds like a fawking garbage truck!
Now that the fan folks are done financing their 3rd vaca home/put 8th kid thru medical school... the price for a new e-clutch fan is about 30-50% (of what it was 10 years ago) so may be time to swap... again
 
I had the same loud noise when starting on my 7.3 and it was indeed the fan stuck in "full throttle" mode. I tested by starting cold and listening if the noise went down after 1-2 min, which it didn't. I ended up changing the fan clutch, problem solved direct.

 
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Shreddinlettuce said:
Benefit to mechanical fan is failure means noise and loss of mpg, not blown head gasket
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I had one fail the other way before though. It would not lock up at all, the test for that was, get the truck nice and hot, shut off, then try to spin the fan, if no resistance then it's bad. The good part is you can jam a sheet metal screw in it to get you home if need be
 
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