Dexcool Antifreeze/Coolant in an Accord?

Thanks, Mike.

Aside: My 91 Civic's Maintenance Schedule says change the coolant every 30k
miles/2 years, whichever comes first.

 

I called Honda Canada customer service, I have a 91 Accord with 265K, pumps
were only changed with the timing belt, rad went at 200K. I change the
coolant every year and always use regular Prestone. I did the same with my
84 Prelude which had 267K when I sold it, the rad and water pump were still
original!! What more can I say?

me??

 

Again - phosphates are not a problem as long as you don't mix in hard
water. Honda Type 2 coolant is only available pre-mixed with deionized
water anyways. AFAIK, Honda coolant does use phosphates.

Havoline's extended-life coolant was the only Dex-Cool licensed product
for years, save ACDelco coolant (which was way overpriced, hard to find,
and probably the same coolant made in the same factories). Now Prestone
has a Dex-Cool license for their extended-life coolant in the silver
bottle.

 

The claim a shelf-life of at least 8 years.

<http://www.havoline.com/products/la/antifreeze_01_tech.html>

"The primary limiting factor in the shelf life of a coolant is silicate
instability. Since silicate will eventually polymerize to silicate gel,
all traditional coolants have a shelf life of about 18 months.Havoline
Extended Life Anti-Freeze/Coolant DEX-COOL is silicate-free and
therefore can be stored for at least 8 years without a problem, provided
the integrity of the container is maintained."

BTW - in addition to the Havoline, ACDelco, and Prestone Dex-Cool
coolants, there's a Chevron one out now. Probably just the Havoline
version relabelled (i.e. Chevron-Texaco merger).

 

Honda Canada appears not to know what is in their very own owner manuals -
what is it about silicate/borate free that is unclear? IMO changing
coolant every year is an unnecessary burden on both recycling and
production resources.

My experience with Prestone regular coolant is contrary to yours... with a
'90 Civic the water pump was bound up tight at ~20K miles after using
Prestone antifreeze mixed with distilled water. Whatever your experience,
it is *not* universally applicable to Hondas - IOW if you propose it as
advice to others here you're going to get contradicted. Have you ever
changed a timing belt & water pump yourself to actually see/feel the
results?

Rgds, George Macdonald

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

 

Hey, I'm not trying to contradict anyone, this is MY experience, the water
must be extremely pure up here or something. But it seems if you own a GM
product Dexcool causes their pumps to fail.

me??

 

It sounded like you were offering advice... advice which goes against
Honda's written advice in owner manuals, service manuals and TSBs and the
experience of others here, including me. Are you now saying you also use
tap water?

Rgds, George Macdonald

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

 

Is there now a problem with tap water?

me??

 

in a lot of places, yes. too hard, too many minerals in it. not good for the
cooling system, since it gets on stuff and clogs passages.

 

Of course. Apart from the possibility of solids coming out of solution and
clogging passages, most tap water is at least a mild electrolyte and some
are quite efficient electrolytes. Putting such stuff in an engine where
you have different metals........<shrug>

Rgds, George Macdonald

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

 

So George, are you saying that my experience with 2 different Honda's and
over half a million kms and not one pump failure is not possible because the
Prestone and tap water are so CRAP?

me??

 

maybe youve got really soft tap water, and its the hard water thats to
blame. .

just do whatever works for you.

 

For the tap water, possibly your tap water is relatively benign, either
because it comes that way or you have a filter. For many others it's a
definite risk. When I'm freezing in my car and the heater is not up to the
weather, or the A/C is causing overheating, I want to be sure it's not
because I used tap water - modern cooling systems, especially heater cores,
have very narrow passages.

For the antifreeze, it might be that your annual change means that the
silicates are not in there long enough to gel out and cause water pump
problems... or possibly Honda water pumps have varied over the years in
their susceptibility to the problem. As a former chemist, I appreciate
some of the things that can go wrong here, though I have not studied the
details of the specific reactions involved.

Either way, my experience is contrary to yours: I've seen water pump
failure at ~20K miles after using Prestone regular antifreeze and I've run
the Honda coolant for the normal scheduled changes with no problems. The
bad water pump I took out, at ~70K miles, could not be turned by hand and
the timing belt was stretched; the good water pump I took out, at 98K miles
after using Honda coolant, looked in perfect condition with just very
slight staining at the weep holes and the belt showed no real signs of
stretch. Since you've actually done that many miles, my question to you
would be: have you actually examined the condition of the water pumps taken
out of your engines and have you examined the corresponding timing belts
for stretch?

If you look back in the archives, you'll find that in Feb '97 or so, I was
one of the first posters here to associate the water pump failure with
silicate, specifically Prestone regular, antifreeze. This came about
because, as I stood at the parts dept. buying my new water pump and
wondering why it had failed, I glanced at the wall where there was a poster
which showed comparison pictures of water pump internals - Honda coolant
vs. Brand-X if you like. Like most people, my inital reaction was
scepticism of marketing BS but after thinking about it I decided to not
take the risk for the small difference in price - $10. or so every 30K
miles, and say $20. every 60K miles with Honda Type 2, is small change for
the peace of mind, vs. the possibility of a wrecked engine.

I think there have been enough posts by others, relating similar
experiences, to confirm the potential danger which is implicit in the Honda
owner/service manuals and their TSBs. Here's a TSB:
http://www.nhtsa.com/TSBScans/sb627281.pdf on coolant leaks in '99/2K L4
Accords, which is not related to antifreeze type but see what it says about
which coolant to use in para #16. Are you going to believe this or
somebody at Honda Canada you talked to on the 'phone?

Rgds, George Macdonald

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

 

Yes George the water quality varies with geographical location and no my
water is unfiltered.
Are we on to something here?, could it be that annual changes are the
answer?
I changed the timing belts in the Prelude myself, the only thing done to the
pump was to change the o-ring once because it was leaking.
The pumps in the Accord were changed by the dealer so I never saw them.
Don't forget we are talking about a 91 Accord here and Honda has obviously
changed their recommendation for newer models since I called them.
Thanks for the wealth of information, and I will not be recommending anyone
use my example but I will continue with Prestone and tap water and will let
you know the minute I have any failures in the future.

me??