Gary, like most things, water vs "coolant" is a trade off. Water of
itself is one of the most corrosive elements  on the planet. So running
it alone cold create problems, even though it may cool a bit better. The
corrosion inhibitors in the antifreeze help with this. It's a realtively
small sacrifice. If your system is in good shape, the additives to the
water (anti-freeze) will be of little consequence, and the added
protections well worth it.

John Rodgers
88 GL driver

gary hradek wrote:

>I have been dealing with a conditon that I believe to
>be a plugged radiator.   I have ruled out most other
>cheaper fixes.   Over the past week I have isolated
>the radiator at the point of the rear most end of the
>big pipes and plugged them with corks and soaked the
>isolated system with 0.2M citric acid for a week.
>Flushing the system with hot water under house
>pressure gave a flow rate about 6 gallons per second.
>The first flush was very black and showed evidence of
>bits of aluminum from what I am hoping to be some
>after market sealer rather than the radiator itself.
>After flushing the system I filled with the orange
>stuff.   What I find intersting about the vanagon
>coolant system is that the flow rate for water alone
>is much faster than with antifreeze added.   This is
>reflected well by the (temperature at idle as seen by
>the gauge) TAI.
>The TAI with water alone is much lower and at position
>determined by the thermostat.   The low speed fan has
>no problem keeping the engine temperature on the red
>light dot even on a very hot day.   Once you add
>antifreeze the TAI goes up above the light unless you
>increase the rpm.   The TIA on a hot day(about 95)
>will respond more slowly to the cooling affect of the
>low speed fan.
>   My question is would I be better off adding less
>antifreeze and more water and perhaps adding some
>after market corrosion inhibitor and water pump
>lubricant?   thanks gary
>
>
>
>
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