On Sun, 11 Jul 2004 08:52:30 -0500, Keith G. Vickers <kgvickers 'at'
charter 'dot' net> wrote:

>Sorry, but I couldn't help it. I'm a recovering pyromaniac and I
>decided to add some extra fuel to the never ending Dexcool fire.
>
>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.

Dexcool is said to be free of all inorganic salts so according to Honda's
recommendations, it does seem to conform.

>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.

I don't see the relevance of "plenty" in the reservoir - there's a max and
a min mark which just have to be observed under the appropriate conditions.
You do have an interesting problem there though: how to prevent the ingress
of air/oxygen in a system where the level is cycling up and down, i.e.
sucking air, with every hot/cold cycle.

>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.

As you noted above, there is "bother" with the "massive flush routine" -
I'd rather just pay the $12. or so for the Honda coolant which I know
works.

>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.

GM's position is that the sludge is due to air pockets in the cooling
system from failing to maintain the coolant level or not getting all the
air out during a drain/refill. There have certainly been some really daft
cooling systems designed... notably VW's pressurized reservoirs which used
to continually leak. Why a mfr would employ a coolant which degrades in
contact with "pockets of air" in a system which is not designed to
self-purge the air is a umm, mystery.

>Let the flames begin. I'm standing back with marshmallows.

As a recovering pyromaniac you ought to know that marshamallows are no
defence... and in fact should be quite familiar with the obligatory nomex
underpants.;-)

Rgds, George Macdonald

"Just because they're paranoid doesn't mean you're not psychotic" - Who, me??