Radiator Fan

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Jami
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Post Thu Jan 12, 2006 4:57 pm

Ok so looks like i will have to sort the oil leak out another day, as long as i keep it topped up!

Can anyone explain how the radiator fans work, because i am not sure if mine is functioning correctly. It does spin, but i can stop it with my hand, all be it with some degree of pain, is this right?
320i SE on 15" BBS in grey with leather to match
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Jami
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Post Thu Jan 12, 2006 5:08 pm

I been reading other peoples comments about other overheating problems. I am right in saying that the fan has an electromagnetic clutch? similar to old Mercs?
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kam-325i
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Post Thu Jan 12, 2006 5:10 pm

No, the fan has a visous coupling, as it heats up, the liquid get thicker, causing the fan to spin more.

Search for the newspaper test, dont stick your hand into a moving fan.....
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Jami
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Post Thu Jan 12, 2006 5:12 pm

Thanks for the tip, but my hand is fine, leading me to the conclusion it is not working.

Where exactly is this viscous couling, in the fan i self?
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gcorky
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Post Thu Jan 12, 2006 5:14 pm

yup your fancoupling will be buggered.around 30-35 for a new coupling .once fitted you will notice the woosh wherrrrring of the new one??


these are actually filled with thick oil and a bimetalic mechanism to lockout at the correct temp


i know cos i disected my faulty one due to curiosity ...lol
kam-325i
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Post Thu Jan 12, 2006 5:15 pm

its the big metal round thing in the middle of the fan. they are prone to wearing out....

Simple test:

Get the engine up to running temp, get a rolled up newspaper, and see if you can stop the fan, if it is easy, viscous if nackerd, hard, viscous is good.
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Jami
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Post Thu Jan 12, 2006 5:15 pm

Cool, but how easy is it to replace, i.e. how long will it take me and what else will i have to remove?
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gcorky
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Post Thu Jan 12, 2006 5:18 pm

32mm lh thread to remove fan.......may need to remove rad like me!
unbolt from fan blades ....doddle



quick note......32mm nut may well be tight .....so tapping spanner to shock it may be required
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Jami
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Post Thu Jan 12, 2006 5:31 pm

Thanks for all the help. looks like something else i will have to buy and fit.
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