[Vwdiesel] Coolant flow through stock oil cooler/heat exchanger

[Libbybapa at wmconnect.com]

In a message dated 11/16/04 1:07:35 PM US Mountain Standard Time, 
scameron at compmore.net writes:


> >After looking at the system and attempting to draw a coolant flow diagram, 
> it 
> >seems that the only flow through the oil cooler/heat exchanger is by
> thermosiphon 
> >when thermostat is closed (therefore doing nothing to warm cold 
> oil-actually 
> >a detriment), and either hottest coolant flowing through "cooler" or 
> >thermosiphon after thermostat is open.  Can this be correct. 
> 
> Not quite. The water pump is arranged so when the thermostat is closed, it
> is pumping coolant throught the block, head, heater core, and bypass, full 
> bore.
> Hence the only reason the heater works in winter (and it sure does)
> Further, if you ever have a plugged rad or stuck thermostat, the heater core
> with full vent fan, is enough to get you home without a boilover. I've done 
> it.
> 
> The thermostat operates TWO valves, the obvious one that opens the radiator
> return passage into the pump,, and the extra disk on the other end that
> closes the bypass at the same time.
> 
> Sandy
> 

I get what you're saying about the double valve in the w/pump.  I will 
reexamine.  Understand that I am talking about the diesel vanagon and not rabbit or 
jetta.  The coolant routing is different.  I will be doing more digging.
Andrew