Date: Sat, 23 May 1998 10:06:09 -0700
Reply-To: "Steven X. Schwenk" <sxs@SCHWENK-LAW.COM>
Sender: Vanagon Mailing List <Vanagon@vanagon.com>
From: "Steven X. Schwenk" <sxs@SCHWENK-LAW.COM>
Subject: Lowering Coolant Temp./Pressure
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After reading all the replies to this idea, it occurs to me that the set
up does not really alter the standard, mid-range operating temp much if
any. It just shifts the temp. range within which the vehicle operates
downward, but only the extremes change...the mid-range operating temp is
still within specs.
The cooler thermostat just means that it will open sooner....and thus
the pressure within the engine coolant loop will not get as high as it
would with a regulat thermostat since the temp will not get as high
before the thermostat opens. Once the vehicle warms up to freeway
operating temps., I do not see how the cooler thermostat will have any
effect. It will be open, just like the stocker would be, cept maybe in
cold winter temps.
By lowering the temp at which the fan kicks in by ten degrees, you just
lower the peak opeating temp...but not the normal highway operqating
temp. By keeping the max temp of the engine 10 degrees cooler, you
reduce the max pressure within the coolant system as well, but you don't
really change the normal, mid-range operating temp.
The overall effect is to lower the peak pressures the coolant system
experiences under the stock set up. General operating temp. might be a
little lower due to the thermostat, but I generally do mostly highway
driving...and slow off road driving. Under these conditions, I think
the difference in actual operating temp once the vehicle warms up will
be negligible, or none. Only the peak temp. will be lower. (As it is
now, my fan only comes on in traffic jams or in tough off road
conditions.)
I was considering this as a means of getting some more time out of my
head gaskets...by lowering the stress they experience under peak
pressures and maybe throwing in some aluma-seal (but i'm still not sure
about that as a preventative measure.). However, my latest inspection
of the heads reveals some traces of creeping corrossion at the head
gasket junction...which means if I want to save the heads and not have
to replace them, but only the gaskets, I better go in there soon and do
it. Of course, if I need a rebuilt transaxle, the heads will have to
wait.
I am not unduly disturbed, yet, by these major maitenance items. The
van is eight years old and has 95,000 miles, has never failed me or
broken down and has not needed much at all in the way of parts or
repairs. It's just time for some mid-life maitenance. It's still like
a new vehicle. I expect to keep it for another 50,000 miles. It will
still be in really good shape even then with 150,000miles. My toyota
pick up, on the other hand, which is the same year and has almost the
same mileage as the van has aged quite a bit more and is clearly beyond
its prime...it'll soon be ready to enter the secondary junker/boomber
market.
steve
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