Keith G. Vickers <kgvickers 'at' charter 'dot' net> wrote in message news:<jgh2f01eono148q32g0mgeee2ctoa4gbi7@4ax.com>. ..

> I bought into the Dexcool hype back in about '98, at which time I
> converted my '88 Acura Legend to Dexcool. The waterpump went bad on
> the Acura in less than 20K miles (a genuine Acura part). I decided
> that this *might* have been a fluke and kept the Dexcool, partly
> because I didn't want to bother with the massive flush routine
> necessary to convert back. I simply changed the pump and topped off
> the Dexcool.
>
> Well, the Acura system proceeded to work flawlessly for another 50K
> miles at which time I sold it in '02 with 185,000 miles. At that
> point the Dexcool in the radiator still looked brand new and the metal
> (that I could see) within the radiator was free of any corrosion.
>
> In the meantime, I had converted my wife's Caravan to Dexcool in about
> 2000. I sold it yesterday with 127,000 miles after having the Dexcool
> in it for over 4 years and about 65,000 miles. Again, through the
> radiator fill neck, the Dexcool and the radiator look brand new.
>
> All of the "official" releases I've read about Dexcool problems have
> said that it is very, very important to maintain an absolute FULL
> level in the radiator and plenty in the overflow bottle so that no air
> gets into the system. I have always kept the system full.
>
> Also note that, when I converted from the "green" to Dexcool, I went
> through about 5 gallons of distilled water to thoroughly flush out the
> old prior to adding any Dexcool, and I only use distilled water in the
> 50/50 Dexcool/water mix.
>
> For the past three years, I've had Dexcool in my old '89 Ford beater
> pickup. Again, the Dexcool is working perfectly.
>
> My point? Nothing, other than to relate my experiences with the
> stuff. I'm sure there have been issues - there are too many folks
> that are having problems, especially with GM vehicles and head gaskets
> / intake manifold gaskets. But I'm not necessarily convinced that
> Dexcool was the cause in all of the cases. I bet "gooey Dexcool" was
> the result of a head-gasket leak, not the other way around.

I've run Dex-cool in Toyotas as old as 1986 and had a problem only
with the very first use. The cooling system had been running green
Zerex, so I cleaned it with oxalic acid, but apparently it didn't
remove all the deposits because several weeks after the switch to
Dex-cool, the overflow tank looked of pea soup. But after a second
oxalic acid flush, the coolant stayed orange for 5 years.

I've heard that Prestone's version of Dex-cool is kinder to some
metals than GM's/Texaco's, is, especially to soldered.