Re: V8 main radiator fan check

[WARATAP@aol.com]

In a message dated 97-06-04 14:18:40 EDT, johkar@teleport.com (John Karasaki)
writes:

<< Could you please do a test for me?  Our V8 is having overheating problems
 when it is sitting at idle.  I think it is caused by a bad viscous coupling
 between the shaft coming from the engine and the main radiator fan.  I
 tested this coupling by holding the fan blade stationary with a screwdriver,
 then having my wife start the car.  I could hold the fan from rotating
 without any real resistance.  I don't think this is normal.  The car is
 overheating while stationary and idling probably because the fan is turning
 but not drawing much air.  If you could do a similar test, I'd appreciate
 it, as the viscous coupling is $140 from Linda (the cheapest I could find --
 no used part was available, but probably not worth buying used anyway).
 Thanks in advance.
 
 P.S.  The car runs very cool when it's moving, even at moderately slow
 speeds, so I don't think it's the radiator.
 
 Regards,
 
 
 John Karasaki
  >>

I really doubt that your viscous cuopling is going bad, though I'm not about
to put a screwdriver in the fan blade for a test.  However, do try the
following, as it might indicate a faulty or corroded thermoswitch.  When
viewing from front of engine you will see a radiator hose that attaches to
the intake manifold.  On this fitting is attached a thermoswitch.  With the
car running (you may want to use gloves, as the engine can be --especially in
your case, quite hot), remove the connector to the switch.  Does the electric
fan come on?  It should be on anyway, especially if the climate control is
set to anything but econ mode.  With mine, when I remove the connector, the
fan switches from normal to high-speed.  Also, you might want to check the
sending unit connection at the bottom of the radiator on the passenger side.
 Sometimes this connector gets corroded, especially if you've driven through
a lot of standing water.

HTH

-Ingo Rautenberg
'90 V8Q 171.5k+