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Viscous Fan - I think mine is always "on"?

chadr

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Let me start by saying that for the nearly 10 years I have owned the car, it has never suffered from any cooling issues. The temperature gauge barely reaches the "half-way" marker and when it does, it is usually on the one day in the year when it's 30C+ and I'm stuck in stop/start traffic...:rolleyes:

However, after reading various threads on and relating to LC viscous fans, I've been paying a bit more attention to mine.

Having done some observations when the engine (5VZ-FE) is cold, very hot and at various stages in between, I've come to the conclusion that my fan seems to be always on? Is that possible?

Now if it was always off, it would obviously be a bad thing but having it always on? Is that a bad thing, a good thing or something that doesn't really matter?

Your advice is appreciated, as always.:)
 
Have you tried to grab it when it's cold? If it's cold you should be able to hold it (carefully) or poke somthing breakable in to stop it- I've used twigs before, if it's not working properly then it will be impossible to hold, or stop.

Don't try this when it's hot... it'll hurt!
 
Have you tried to grab it when it's cold? If it's cold you should be able to hold it (carefully) or poke somthing breakable in to stop it- I've used twigs before, if it's not working properly then it will be impossible to hold, or stop.

Don't try this when it's hot... it'll hurt!
How many fingers do you have left? :o
 
A rolled up newspaper does the job nicely. saves fingers. :think:
 
How many fingers do you have left? :o

We had one viscous fan so bad in Australia that you could actually hold it with your hand... hence the warning, and the suggestion to use a twig, although I think the newspaper (confetti) idea is better.
 
Have you tried to grab it when it's cold? If it's cold you should be able to hold it (carefully) or poke somthing breakable in to stop it- I've used twigs before, if it's not working properly then it will be impossible to hold, or stop.

Don't try this when it's hot... it'll hurt!
.
I will give you a shout to bring your hands when I need to check my VF is working.
Not with my fingers, never in a month of Sundays

Gra.
 
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Never grab the fan even if it is not working, my mate lost the top of his little finger when he accidently toched mine........

The fan works by moving fluid arround in chambers inside the fans clutch increasing the drag as the temprture rises thus making the fan run faster. The viscous fan is not designed to run at full chat for long periods of time and if it does you run the risk of the blades shattering and destroying the rad. If the fan is working well then it should never reach full engine rpm's it is always a percentage of the total depending on how hot the engine is.

If you fan is running at full chat you will hear the roar of the air being pulled through rad over any other noise it is loud. You should get an initial roar when you start the engine and first drive off whilst the centrifugle forces throw the oil round from being settled at the bottom of the chambers then should go quiet.

There is no real way to test it unless you have a tacho to measure the engine and fan revs, a temreture gauge to measure the engine and bimetalic spring in the centre of the fan and then do some fancy maths to work out your percentages.

So the simple answer is yes the fan is always on its how on it is...

Hope that helps.

Steve
 
Have you tried to grab it when it's cold? If it's cold you should be able to hold it (carefully) or poke somthing breakable in to stop it- I've used twigs before, if it's not working properly then it will be impossible to hold, or stop.

Don't try this when it's hot... it'll hurt!

Only if you want to do this..... :auto-ambulance:
 
Thanks Steve - that explains a lot.

I do hear the "roar" as you describe but only when the engine is VERY hot - so I suppose the fan is working as it should.

Cheers.
 
start the engine from cold, throttle it to about 1500rpm and hold it there, after about 30 seconds you should hear the fan go from a roar to being quiet, when it gets red hot it will roar again
 
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