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Discussion Starter #1
I noticed some drippy substance on my radiator fan blades yesterday. The drips appear on every blade to a varying degree. Any idea what it might be from? A semi knowledgeable friend said it might be my fan blade motor going bad while another friend said "they all look like that". No obvious leaks from under the car. What gives??
(A cursory search turned up nothing useful, feel free to point me to the appropriate thread!)

Thanks!
 

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I would guess the fan clutch has puked it's fluid. The clutch's temperature-dependent lockup function is based on that fluid being where it should be, so this isn't a good sign. Do a search here for a procedure to check the function of the fan clutch, but I assume yours is not functioning correctly.

Tell your semi-knowledgable friend that there is no motor on a belt driven fan.. :)
 

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I would guess the fan clutch has puked it's fluid. The clutch's temperature-dependent lockup function is based on that fluid being where it should be, so this isn't a good sign. Do a search here for a procedure to check the function of the fan clutch, but I assume yours is not functioning correctly.

Tell your semi-knowledgable friend that there is no motor on a belt driven fan.. :)

^ Disco
 

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Discussion Starter #7
Not too bad, about the same price as a night at Los Gatos right? :) probably less chance of puking after ordering a fan clutch too... so that's nice.
 

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I have one that I bought but won't install because I'll be installing an electric fan. PM me if you want it.
 
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You'll need a special tool as well (got it from Turner Motorsports) to remove the fan clutch and a big ***** 32mm wrench (I got mine from Home Depot).

Edit: I should also mention to test the fan blade for looseness or notchy feeling as you spin it by hand (with the engine off) before you go spend some money. It is possible you also swallowed a massive dragonfly or some other insect and it got through to the fan blades in question.
 

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I have one that I bought but won't install because I'll be installing an electric fan. PM me if you want it.
Sounds great Diny! Is it the OEM BMW fan clutch? What's the advantage to using an electric fan over the stock setup?
 

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Discussion Starter #13
Good point there. I'll mail you mine, Nathan, buy me a beer or two at the next ///ECFest...
That's dang nice of you! I've got a buddy who may have one actually. I think I even have a 32 mm wrench too (think that's the same size as the axle nut on my last motorcycle)
 

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Sounds great Diny! Is it the OEM BMW fan clutch? What's the advantage to using an electric fan over the stock setup?
Yes, OEM. I also have the tools around here somewhere.

The advantage is that it doesn't crap out like the fan clutch. I've had luck with mine but others, not so much.
 

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Only other special tool you should need is a large lump hammer (2lbs min) the bigger the better, and a well coordinated smack/contact with the 32mm wrench in the right direction. Clockwise for this beast as it's a left hand thread. (Oppostite than normal). Hardest part for me was getting the clutch started back on the left hand thread, not used to turning the wrong way. Otherwise it's about a 10 minute job. You may want to clean the oil residue off the fan blades so dirt doesn't stick to them and throw the balance off.
 
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Discussion Starter #16
You all are awesome. Thank you so much! It's pretty damn tight in there... I might have to use my 7 yr old with his tiny hands... :)
 

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Also check the fan blades for any stress cracks, etc and replace the fan itself if anything looks suspicious. These have been known to explode and do damage to the hood and other surrounding components when they let go
 

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You all are awesome. Thank you so much! It's pretty damn tight in there... I might have to use my 7 yr old with his tiny hands... :)
Yeah that was the hard part about getting the clutch threaded back on the fan hub. Getting hand/wrist at the right angle to work around the shroud, stay perpendicular to the threads and turn it at the same time.
 

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Also check the fan blades for any stress cracks, etc and replace the fan itself if anything looks suspicious. These have been known to explode and do damage to the hood and other surrounding components when they let go

I think the main issue with the fan blades letting go is the clutch being so far gone past all the oil leaking out that the clutch has seized back up and is locked at full speed of the pulley. Combined with aging brittle BMW plastic the fans come apart. So if the clutch is new fan will probably be OK, but the blade set is relatively cheap so one can replace it for peace of mind you desire. This seemed to be more of an issue on the 540i which runs a bit hotter.
 
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