Prestone LowTox + cooling system flush

Honda Type II has a longer service life but I don't think is really classified as "extended life", is it? I've done 30K miles on my '92 Integra with Honda Type II and no sign of problems. I'm baffled by the resistance to the stuff. Are people really willing to gamble a wrecked engine for the sake of saving $10. or so every 60K miles

Rgds, George Macdonald

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

Many "extended life" or "longer life" coolants use a variation of the "organic acid" corrosion inhibitors. I know Dex-Cool coolants were the first. Toyota's new "long life" (60K miles) coolant is; I just picked up a bottle and one of the ingredients is "organic acid salts". I suspect Honda Type 2 coolant is just another coolant using organic acid technology. Read the following (sounds like it's from a Honda marketing flyer):

"Honda's formulation for coolant does not use silicates or borates to enhance the corrosion protection for aluminum components. Instead, Genuine Honda antifreeze/coolant uses a proprietary organic corrosion inhibitor."

From what I can tell the dex cool appears to be a problem because people just assume everything is fine and they don't bother checking their coolant levels when they should and they are probably believing the 5 year 150k mile BS. Personally I plan to change my DexCool in my Honda every year or two and I really don't anticipate any problems. I will post on this further if it becomes a problem.

I didn't get the DexCool because of the supposed long life but for the silicate free properties.

CaptainKrunch

If it is just one ounce, why not just use water?

My guess is that a good deal of owners of these GM cars aren't as diligent at checking under the hood compared to the average import car owner.

There's some pretty good indications that these "extended life", "long life", etc coolants (perhaps even Honda Type 2) are all just variations of similar organic acid technology (OAT). The link you gave seemed to criticize the OAT concept rather than individual implementations.

However - it seems to me that Honda has sensibly used this new coolant technology, and applied more conservative change intervals than other carmakers. GM seems to have been the first, and perhaps jumped out of the gate claiming way too much. Sort of reminds me of when Mobil 1 came out with the suggestion to drain it once a year with filter changes.

I suppose the exact formula varies from brand to brand but the URL I provided decribes it as "moderately silicated".

Rgds, George Macdonald

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

"Extended life" coolants have been around for >40years. Dex-Cool is just a newer twist on the story and according to the URL I've given it is "moderately silicated". I gave up experimenting on coolant the first time I saw the results of just using Prestone off the shelf. If you want to try to find an equivalent which saves you $3./year, please *do* report back on results.

Rgds, George Macdonald

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

Havoline Dex-Cool is clearly labelled as silicate-free. A previous version of Prestone Extended Life was labelled as silicate-free, although I don't recall seeing that description on the current Dex-Cool licensed version.

I still hear that silicates aren't supposed to be in any Dex-Cool system if it can be helped.

I'm referring to the current offerings of extended-life coolants recommended by car manufacturers. If I recall, very few carmakers recommended/mandated their use, and that that didn't surely didn't think much of the "extended life" claims. Now there are a whole slew of organic acid coolants mandated by carmakers, and the evidence seems to be that Honda Type 2 is just another one. The URL you provided seemed to primarily criticize the reliability of the technology itself, rather than any particular implementation.

Again - The Havoline/Chevron labelled Dex-Cool coolants are silicate-free. Perhaps Prestone Extended-Life isn't (they don't say either way).

"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."

So - right now I'm trying to flush the my cooling system of the Prestone LowTox with two changes of water. Sure - I could try to use Honda Type 2, but then I'd either end up with less than a 50/50 mixture, or I'd have to use four gallons of Type 2 (about $50) to get close to a 50/50 mixture. I've got the Havoline Dex-Cool already, and I should be able to bring up the concentration with undiluted coolant.

OK - I looked at the Prestone website. I suspect that the GM

6277M standard for Dex-Cool coolant specifically prohibits the use of silicates.

"Q: Does Prestone® Antifreeze/Coolant contain phosphates?

A: For those consumers who would feel more comfortable using a phosphate-free antifreeze, our Prestone® Extended Life 5/150 Antifreeze/Coolant is phosphate, silicate, and borate free."

Sorry - I got mixed up between the Glysantin G 05 and Dex-Cool - it's the former which is "moderately silicated".

OK but would you normally buy a product which is the subject of so much controvery and has an active class-action suit against its mfr and suppliers?

Rgds, George Macdonald

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

Not sure what you looked at at the URL I gave but the impression I got from what I saw was that it is Dex-Cool which is the culprit. We know, of course, that the cooling system is a neglected part of the system by many people - once per week is most mrfs' recommendation for checking *all* fluid levels/condition and yet many simply refuse to lift the hood. All the same the leak reports are on the high side here and even one in this very thread.

While Honda's Type II may be just another one, it does not mean that the OAT is identical and I doubt that I'll take advantage of its "extended life" anyway. The fact is that even Honda Type I coolant was necessary to avoid water pump problems. If assumptions are to be made here, IMO it would be that Honda has a coolant which is *still* compatible with its pump seals/bearing *and* has this "extended life" attribute.

Rgds, George Macdonald

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

First of all - when I got my Integra, I did the first coolant drain at

30K miles (manual said 45K), and every 15K after that until a rad hose burst. I used regular Honda coolant (not premixed). When my rad hose burst and I started using Havoline Dex-Cool, I was going to do the regular 15K changes that I'd done previously, although I did let it slip to about 18K.

Everything I've ever heard about this water pump "compatibility" is that silicates are the culprit - either by wearing away at the seals or gelling and clogging them up. As long as I (or the next owner of my car) is still replacing coolant every 15K miles/once a year, exactly what benefit will I get from using Honda Type 2 over (silicate-free) Dex-Cool? I doubt they'll pay if it fails on a car with 130K miles.

I was flushing my system to remove as much Prestone as I could. How would I use Honda Type 2 coolant to bring up the concentration even close to 50/50?

Haven't heard of that name before.

As far as I can tell, the problem is with a combination of improperly monitored cooling systems along with the extended life claims. Most of the problems mentioned in that article seemed to arise from large amounts of air in cooling systems. It would seem that the problem could have been avoided if owners just checked their reserve tanks every once in a while. I'd venture that owners taking care of Hondas in the same fashion would likely end up with similar problems.

I changed my coolant every 15K miles. The Dex-Cool product was cheap and seemed to meet the recommendations for a silicate-free coolant.

This doesnt prove anything except that you can get antifreeze formulations that are free of phosphate and silicate.

How WELL they work, with respect to engine corrosion, seems to be as nebulous as the synthetic versus dino oil controversy.

I have done these tests under laboratory conditions, and I can tell you that everything is a compromise.

However - that is the one thing that seems to be stressed when it comes to replacing the coolant in Honda vehicles.

Sure. I've heard that since going to Dex-Cool, GM has had considerably fewer warranty claims for water pumps. OTOH - they seemed to have run into a slew of corrosion problems. I don't know exactly what to make of some of these warnings against Dex-Cool. Is my water pump going to explode? Is my brand new radiator going to rot away? Is it some sort of bad interaction? Will it start springing up leaks? The real question I have is, given that I've already used it in an emergency, i

However - what I plan on doing is draining (or advising a new owner thusly) the coolant every 15K miles. I doubt this would overly stress the anti-corrosion properties of the coolant.

It isn't necessarily an issue of stressing the corrosion inhibitive properties of the coolant. By changing so frequently, you certainly aren't harming anything.

Changing every 15,000 miles is probably overkill, but do as you like to protect your engine.

I doubt there is anything super special about Honda antifreeze versus others. I'll have to take a look some day and see what they really put into that stuff.

In the past month, I've had three coolant changes. The first was with regular Prestone at a shop when my radiator was replaced. The next was with Prestone Low-Tox (I thought it was silicate-free or at least low silicate) with a detergent flush. The thinking on this board was that it was a bad idea, so last Sunday I gave it two water flushes and finally Havoline Dex-Cool.

That was what Prestone always recommended - 15K miles or every year. I doubt I'm the only one who went that far. I guess the three coolant changes in the past month are overkill, but I was just trying to undo two instances where the wrong coolant might have been used. My last coolant change before the radiator sprung a leak was maybe 18 months.

Now I have about 20 gallons of used antifreeze sitting in the garage, from years of coolant changes. My county has a haz waste facility, but they won't take more than 15 gallons or 125 pounds - something about the transport limit by state law without a license. This is one downside, but I guess I can make a couple of trips, and I can get rid of those oily paper towels I've been collecting.

The sentiments seems to vary from, "What's the big deal with Dex-Cool" to "Why take your chances?" to "You're just asking for trouble". Toyota lists "organic acid salts" in their "Long Life Red" coolant, while Honda lists their corrosion inhibitors as proprietary. I'm also ticked off that they're charging as much for the 50/50 Type 2 coolant as they did for their previous undiluted coolant.

That sounds like it falls under the same line as oil producers recommending

3000 mile oil changes, i.e. "Good for Business".