Cooling Fan Clutch

[Clone of the Mean]

Can someone please explain this to me. I have a 94 Runner my kid has had up in Flagstaff for school. Now it's home and I've resumed ownership. When I first drove it it sounded like a B 29 lumbering down the runway. I replaced the fan clutch. It was frozen solid. The new one was as quiet as could be, then began to roar just like the other one. It spun freely, just loud as hell. The latest one roars but gets quiet pretty quickly, but it gets loud after every stop I make.

What is causing this? Am I just getting crappy clutches? Is it normal? It's been so long since I've driven this Runner so I don't remember any noise.

And I guess the ultimate question is, what exactly does the clutch do? How does it function? I thought I knew…..

 

[southbay]

Pretty sure its purpose is to unlock and let the fan freewheel at higher speeds ( and lower )when its not really needed, saving power. When its gets hot a thermostatic spring or other device? will lock the clutch so it spins with the engine. When it cools down it will go back to freewheeling.

 

[Clone of the Mean]

In a nutshell, that's the way I see it. I'm in Tucson. his thing gets hot and stays hot in the first 3 minutes of the day. I've just never had one roar as much as on this Runner.

It's been 5 years since I've driven it a lot, but now I drive it every day. It's a noisy little bastard….. Even in the dead of winter ( the low 40's).

I listen to others and they're quiet compared to this one. Even other Toyota vehicles.

 

[91'4bee]

Well if the fan is keeping it cool then I would leave it alone. Our 2nd gens are just notoriously loud(all around). Mine is almost never loud, due to fan, but summer usually changes that(mainly because of AC use). If it is really bothersome put a louder exhaust on to drown out the fan, convert to an electric fan, or try flushing the whole cooling system (with new thermostat) to see if that helps keep some temps down under the hood...:blah:

just some ideas hope this helps