[s-cars] Fan viscous clutch died today

[Tom Green]

> Previously written:

> Date: Wed, 26 Nov 2003 19:06:26 -0500
> From: "Bob Rossato" <bob.rossato at att.net>
> Subject: RE: [s-cars] Fan viscous clutch died today
> To: "Vincent Frégeac" <vfregeac at sympatico.ca>,	"Kevin Day"
> 	<kday at ultrameta.org>, <s-car-list at audifans.com>
> Message-ID: <LOBBINDDLNBLMPCDBAAFIENJJMAA.bob.rossato at att.net>
>
> Vincent Frégeac said:
>
>> Hi all,
>>
>> The fan viscous clutch died today. Fan is running all the time. So, it
>> raises a few questions:
>> -        Is it a repair or replace item?
>> -        What is the PITA factor?
>> -        Is it easy to find besides dealers?
>> -        Is it shared by other model?
>> -        Is it a common failure aka is it worth buying a used one?
>>
>> Thanks for your usual wisdom,
>
>
> And Kevin Day added:
>
>> If the engine fan is spinning when the engine is first started up in 
>> the
>> morning, after sitting all night in <40F temperature, does this 
>> indicate
>> a probable or certain failed viscous fan coupling?
>
> I believe the fan will run all the time.  However, if you look 
> carefully you
> will note that it is running in the opposite direction of engine 
> rotation.
> So, it's not really engaged as much as it is counter-reacting to the 
> drive
> pully rotation.  It can be stopped by applying slight pressure on the
> outside ring with with your fingers, or maybe something more 
> expendable if
> you're the careless type (Don't try this at home kiddies).  At least 
> mine
> does.  Once it heats up and locks on then it should rotate with the 
> engine
> and pull air through the radiator.
>
> Bob

This is a replace me item.   It usually fails in the clutch siezed 
position.  The PITA factor would be trying to stop the fan if the 
clutch is siezed.  Also, the air loads on the locked fan at highway 
speeds are pretty high, creating the noise.  It has caused blade 
failure, belt failure, etc, sending the loose parts forward generally, 
in the direction of the tender $$$$ radiator.   PITA to say the least. 
:-)  A used clutch is about as useful as a used condom, about as 
reliable also.  YMMV

Tom '95 S6