Dexcool Experience

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.

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.

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

Keith

 

I killed 3 Integra water pumps with green Prestone in 1991 or
thereabouts. One failed in a mere 6 weeks. Certain death. Isn't it
interesting that Prestone has never admitted the problem. Can you say
"class action."

On the other hand, I changed my 1996 I30t to Dexcool at 37,000 miles.
Pump seal failed at 93,000. Not an outstanding life, and not what I
hoped for, but not terrible. Suffice to say that I do not believe
that Dexcool will "extend" pump life, although this is Texaco's
position.

Never the less, I would not use anything other than genuine Honda
coolant in a Honda product. Partially because I learned from my
Integra experience just how easy it is to screw up a Honda pump. It
isn't worth a few extra bucks to go experimenting.

JM

 

I know this has been beaten to death in here, but paying over $10 for a
diluted 50/50 mix of Honda coolant at the dealership is absolutely absurd.
Of course my thoughts may change when my car breaks down due to Dex-Cool.

CaptainKrunch

 

At one point my (purchased new) 91 Civic's water pump failed prematurely after
something less than 40k miles and a couple of years. I suspect the independent
shop that had done the last timing belt/water pump replacement used non-OEM
coolant. But I know I had replaced the coolant with green Prestone in the past,
so I might be the one to blame.

The car is now 1.75 years into a Havoline Dex changeover (this followed a very
thorough flush of the cooling system). I changed the thermostat a few months ago
and the Dexcool looked very clean, though that may mean nothing.

I plan to change the Dex in a few months, following the two year rule, despite
the advertisements on the Dex saying it will last longer. Why am I not heeding
the advertisements? Because of (1) all the suspicion here over non-OEM coolant;
(2) the lack of data on Dexcool for Hondas; and (3) my own experience with
non-OEM coolant.

When there's more positive data for Dex in Honda engines, I might reduce the
coolant changeout frequency.

Despite this little radiator coolant experiment, I do not plan on doing a
similar one with synthetic oil in my car's engine.

Caroline
(Pass the marshmallows.)

 

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.

 

I don't know about whether I would try to extend the coolant drain
period. I thought the big deal with Dex-Cool is that its "mojo"
comes from being installed in a brand new cooling system. The
corrosion inhibitors supposedly form a protective coating.

I had Dex-Cool in several cars, and none had any coolant related
problems. For one - I mixed in Dex-Cool after I'd only used green
Honda coolant in an emergency. The rad did crack at the top, but
that wasn't coolant related (it was also at 130K miles).

It hasn't been around that long to know. However - there is the
chance that there wasn't any reformulation - just that they got the
GM approval and license.

 

It seems inexpensive compared to the price of a new water pump,
doesn't it?

Ron

 

yes it is certainly cheaper than a new water pump but it isn't a choice
between running Honda coolant or buying a new water pump. If it were that
would be a valid argument. I for one am not convinced that simply running
Dex-Cool and changing it every couple years is going to harm anything. So
the choice is between expensive Honda coolant and the more inexpensive
Dex-Cool.

Captainkrunch

 

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

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.

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.

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.

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??

 

just curious... were they all OEM honda pumps? or aftermarket? or rebuilts?

i have never used the green stuff in any of my japanese vehicles. no
probs with the orange stuff, everything looks nice and shiny inside.

especially if the specs call for silicate and phosphate free coolant

 

thats what i use... mixed 50/50 with distilled water, and changed every
3 years. everything still looks new, and the old coolant i drained was
clean.

 

i think we can all agree that the "green stuff" is a no-no.

 

mebbe. were they asking for special coolant back then?

it means its not picking anything up... which means it isnt leaving
anything behind, like scaling or corrosion. thats a good thing.

you could probably go 3, but whatever floats your boat. i dont buy the
100k claims myself either.

so you arent going to go synth? or are?

 

I assume this is a philosophical issue for you, because that $10/per for
Honda coolant is peanuts in terms of the total cost of ownership of a
car, even if you changed it every year. I'm probably relatively
'poorer' than most in this group and even I don't give s second thought
to buying that stuff. It certainly isn't going to affect my standard of
living much... nor probably yours.

 

Is it not true that the color of the coolant does NOT guarantee the
composition of the product? Aren't there examples out there of red or
orange coolants that are chemical equivalents of green Prestone? (I
thought I remembered reading somewhere that this was the case.)

snip



Ron

 

Question: would switching from Honda coolant (as opposed to the
"green stuff") to Dexcool require the "massive flush routine?"


Ron

 

Do you mean does the 91 Civic's owner's manual say to use OEM coolant?

The manual has a paragraph giving a layperson's description of the aluminum
engine and its cooling chemistry needs. Then it says, "se only a Honda
**RECOMMENDED** anti-freeze coolant. CHECK WITH YOUR AUTHORIZED HONDA DEALER."

(The caps and emphasis are what's in the manual.)

Years ago I read the green Prestone labeling. It said something re-assuring (to
me at the time, in my naive "youth") about its being okay for my car.

Now, with more experience, I won't ever again put green Prestone in my Civic.

I believe you. I just don't have enough experience (after three or four drain
and fills in my car's life) to judge well. My vague recollection is, yes, the
green Prestone I drained twice or so in the car's life did not look new. Had
little bits of junk in it. The couple of cups of orange Dex I drained a few
months ago for the thermostat replacement looked, well, new.

I'm thinking you're right, but I am sweating a bit the 2001 premature water pump
failure, after 2 years and only 18k miles, with green Prestone and probably a
non-OEM pump.

Live and learn, though things are looking good after three years and 34k miles
on the latest (non-OEM?) water pump, 1/3 of its life on green Prestone, half on
the orange Dex, though again, I did a really thorough coolant flush 1.75 years
ago when I changed over.

I am not putting synthetic oil into my (old) car. I buy the seal theory for now:
The various old engine seals in my car now well-impregnated with NON-synthetic
oil may fail when they come into regular contact with synthetic oil.

But if I had a new car, I would strongly consider synthetic oil, and I suspect
I'd be changing it no more than every 10k miles.

One more anecdote on this: A stroke of luck last year gave me an elderly
gentleman neighbor who is a serious classic car enthusiast. Last week he told me
one of his buddies does not change the synthetic oil in his car more often than
30k miles (and some time limit). My neighbor is trying this frequency on his
fairly new SUV. He has no concerns. The guy's pretty bright, cautious, and
fastidious in his garage and with his several cars, so I have stored this in my
anecdote database.

I'll keep an eye on how well his car is doing, too. ;-)

 

*&^%$#

That should be 1/3 on green prestone, 2/3 on orange Dex, roughly.

 

||On Sun, 11 Jul 2004 12:53:02 -0700, "CaptainKrunch"
||
||>I know this has been beaten to death in here, but paying over $10 for a
||>diluted 50/50 mix of Honda coolant at the dealership is absolutely absurd.
||>Of course my thoughts may change when my car breaks down due to Dex-Cool.
||>
||>CaptainKrunch
||
||It seems inexpensive compared to the price of a new water pump,
||doesn't it?

Judging the quality of a coolant by the life of the water pump is not a valid
test. Water pumps do not fail because coolant attacks them. They fail because
belts are overtightened, they fail because something in the accessory pulleys
imparts a vibration, they fail because a bearing or seal had a factory defect,
they fail because grit in the coolant cuts the seal etc.
Corrosion of cooling system components is the issue, and then only in a
system that is imroperly maintained, or where the coolant is changed to one
incompatible with the metals it comes in contact with.
A water pump bearing/seal is an integrated unit that is impervious to all
commonly used automotive coolant chemicals. Mechanical damage during assembly
or accellerated wear due to environmental mechanical problems is the only thing
that will shorten the service life of a water pump.
Although an alien tractor beam has been known to bend the shafts occasionally.
Bit that's anoterh thread entirely
Texas Parts Guy

 

Others here have had such experience(s).

"Incompatible" is the operative word here.

Rgds, George Macdonald

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