Cooling Fan Clutch Bad or Good???
- Thread starter gooch06
- Start date
With the engine off, reach around the fan and feel the outside(side to the radiator) of the clutch. Does it have an oily waxy residue? That would be a sign of a leaking clutch. Alot of fan clutches spin for a few seconds when first started. If your's still sounds like a jet after fifteen seconds during a cold start up, then I would call it bad. A fan clutch that stays engaged will suck HP and gas big time. Hope this helps.
Well, the fan is on a clutch that always has some tension.
Check to see how easy it spins when the car is cold (and off).
If you spin it, just a few blades should pass after you let go.
But, with new fan clutches only being $50-$100, if you have any real doubts, buy a new one, becaue if that thing is locked up, it will almost tear the water pump off the car. I've seen it lock up, come off, and go through the radiator.
Check to see how easy it spins when the car is cold (and off).
If you spin it, just a few blades should pass after you let go.
But, with new fan clutches only being $50-$100, if you have any real doubts, buy a new one, becaue if that thing is locked up, it will almost tear the water pump off the car. I've seen it lock up, come off, and go through the radiator.
2000xp8 said:
Exactly. It will always spin, but when cold it will not spin as much. Usually they just loose all tension and don't pull air, but lockup, very rare. Even if locked up I don't belive it would tear off the waterpump and such, I think the fan blades would break off first.
Check the plastic fan for cracks, if so replace that too. I would look into what Hissin50 has, a heavy duty clutch and a metal fan blade. Then again, forget it and get an electric, BM, Taurus, MarkVII, ect...
PurpleStripes said:
Not exactly, but it does take a minute or two to warm up. My 250 sounds like it will take off when the fan clutch is cold. After a couple of blocks, it settles down.
stang22
Active Member
hllon4whls said:
My Yukon does the same thing.
Every fan clutch of mine that has went out always started leaking. You wouldn't notice until you took the clutch off and see all the dirt sticking to the oil/grease.
Copied from a site I found on the web. Sorry, not trying to beat a dead horse here...
Check for oil streaks (or dust collected on oil streaks) on the fan clutch. It's a sure sign that the internal fluid that provides the clutch action is leaking.
To check for a worn bearing, with the engine off, grasp the fan blade on either end and check for lateral movement. If there's more than 1/4" of side-to-side movement, the bearing is worn and the unit needs replacement.
In checking for proper fan clutch operation, first run the engine until operating temperature is reached. Next, with the engine off, give the fan blade a gentle spin. If it rotates more than twice the clutch is worn and needs replacing. If fan rotation is rough or noisy, or the fan fails to turn, the unit is worn out and needs replacement.
Sometimes it's tough to spot leakage with regular engine crud on there. The other standard test for a fan clutch is to compare the amount of spins it has on shutoff when it is cold, versus when it is hot. Cold (after a bit of warmup since the juices in there do need to get moving) it should freewheel a bit when you shut down. But get it good and hot, and it should snap to a stop within 2-3 revs. If it continues to freewheel on shutoff when it is hot, then it's likely shot. Also, you can suffer a permanent lockup, in which case it will always snap to a stop, regardless of temp. The symptom for that is usually a constant whooshing noise from the fan clutch being always engaged and forcing maximum air.
Now for my personal rant: I have been through more than a few fan clutches on various cars over the years, and I am convinced that it is worth the extra money to get a factory Ford fan clutch. I find that they work right -- spin freely when cold, but lock up good when hot. I find that aftermarket fan clutches are almost always too tight, which means that they cost horsepower. As a rule, aftermarket clutches sold as "stock" have seemed like a real drag to me. My theory is that they do it on purpose, since most people in the market for a fan clutch get there because of overheating, and a tight clutch can't hurt that. But you can really feel the difference from a properly working fan clutch to one that is too tight, and that difference is pure HP. So don't feel bad spending the extra bucks for a genuine Ford unit.
Now for my personal rant: I have been through more than a few fan clutches on various cars over the years, and I am convinced that it is worth the extra money to get a factory Ford fan clutch. I find that they work right -- spin freely when cold, but lock up good when hot. I find that aftermarket fan clutches are almost always too tight, which means that they cost horsepower. As a rule, aftermarket clutches sold as "stock" have seemed like a real drag to me. My theory is that they do it on purpose, since most people in the market for a fan clutch get there because of overheating, and a tight clutch can't hurt that. But you can really feel the difference from a properly working fan clutch to one that is too tight, and that difference is pure HP. So don't feel bad spending the extra bucks for a genuine Ford unit.
Sam, well said. I can tell ya that the Imperial HD clutch is very tight. That is just what I wanted - ambient temps here are hot. I agree that the clutch is likely robbing some HP, but it is a compromise that I am definately willing to make.
FWIW, that clutch with a metal replacement fan sounds like a jet engine (people have thought it was a blower).
FWIW, that clutch with a metal replacement fan sounds like a jet engine (people have thought it was a blower).
HISSIN50 said:
My dad filled his 8 clutch with silicone. It was an 8 blade plastic fan. 4 speed with 4.56 gears. People would stop on the streets and look to see what was coming. Good ole 77 chevy luv half breed isuzu.
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