[Vwdiesel] Hole In Thermostat ?

LBaird119 at aol.com LBaird119 at aol.com
Sat Mar 27 10:44:58 EST 2004

> While we definitely don't have cold winters here in Seattle, I am not
> sure that I understand this part.  How does the severity of the winter
> effect the importance of having a bleed hole?

  Oops, meant to 'splain that one.  Although it's a small hole, coolant 
does go through it.  These engines don't put out a lot of heat so if 
it's zero out, and you're running across town, you lose enough heat 
to affect how much heat you get from the heater.  Warm weather and 
you'd never notice.  I wouldn't have thought this possible except for 
one winter where a week of putzing around town never melted a bit of 
the snow that had piled up around the Dasher's radiator.  A small 
bleed hole may not be significant but again, I'd never seen such a 
thing happen especially on a car with a bleed hole in the stat.  <shrug>
> By this you mean disconnecting the upper radiator hose at the radiator
> and filling the system through this hose.  Is that right?


> I spent some time contemplating my cooling system and tried to imagine
> what would happen if I poured the coolant into the expansion tank.  It
> looks like the problem arises because there is no easy route for the
> displaced air to escape.

  Correct again.

> So when you use the upper radiator hose method, the coolant enters the
> flange on the head and flows down through the other hose to the water
> pump.  The displaced air can then flow up through the head and exit
> through the same flange and hose.  Is this correct?


> Now what about the radiator?  Because the thermostat has been closed,
> none of the coolant has entered the radiator.  If the upper radiator
> hose is reconnected and more coolant is added to the expansion tank,
> how does the air in the radiator escape?

  It goes out the little circulation hose that exits the top of the radiator 
and goes into the top of the reservoir.  Usually after running and letting 
it cool the first time, you can add another pint to a quart.  Probably 
from air in the heater.

> This Rabbit rebuild job has impressed on me how much basic stuff I
> still have to learn about these machines.  Perhaps I need to apply
> myself more.  My excuse is that I only have a single Rabbit diesel
> which has been very reliable.  Because of this I don't work on it
> frequently enough.  Got to move out of this apartment and get some
> land so I can start accumulating them.
 With the high fuel prices, people will be eyeing all us diesel hoarders 
with envy.  ;-)

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