Well I got confirmation the other day. GM will no longer be using Dexcool as factory fill. Zerex G-05 will be used. From what I am being told it might be dyed orange, like current dex-cool or they may go to another color. I do not know the time frame on when the switch will happen though. I say 05 models but cant confirm. Once I know any more I will pass it along. John O
Dexcool No Longer GM Factory Fill!!!
- Thread starter Ojustracing
- Start date
- Status
I just flushed my system and filled up with dexcool.
Should I keep it for 75,000 miles or flush it early? Should I go back to green?
Should I keep it for 75,000 miles or flush it early? Should I go back to green?
[/QUOTE]From where did you get this confirmation? [/QB][/QUOTE]
Right from my Valvoline Distributor. I know it is not public yet. Once I get the supporting paper work I will speak more freely on the details. All I can say is what I've told you. John
Right from my Valvoline Distributor. I know it is not public yet. Once I get the supporting paper work I will speak more freely on the details. All I can say is what I've told you. John
If GM has, indeed, decided to go to Zerex G-05 as factory fill coolant, they'd have to be nuts to go with orange dye. I can just see the legal headaches for GM of independent shops or owners pouring DexCool in as top-up and driving merrily away for extended CCIs. (out of the frying pan, into the fire...) Don't think it could happen? We all know millions of car owners continue to slavishly buy oil filters in orange boxes because old habits die hard. Until confirmation of this move is forthcoming from a source other than a Valvoline distributor, I'll consider the "announcement" strictly as an unverified early radar contact that bears scrutiny.
i'm not suprised, their was a big class action law suit over Dex-Cool.
http://www.cwcd.com/CM/ClassActions/ClassActions35.asp
curious what is the recommended dain interval for Zerex G-05?
http://www.cwcd.com/CM/ClassActions/ClassActions35.asp
curious what is the recommended dain interval for Zerex G-05?
Good riddance Dex Cool.
You can add me to the list of people who think that Dex Cool sounds good....but believes that this OAT technology coolant has something wrong with it.
I had nothing but expensive problems with every car that I switched to Dex Cool.
I'm thinking that the Zerex G-05 might be worth trying.
You can add me to the list of people who think that Dex Cool sounds good....but believes that this OAT technology coolant has something wrong with it.
I had nothing but expensive problems with every car that I switched to Dex Cool.
I'm thinking that the Zerex G-05 might be worth trying.
So I learned...the hard way.
Of course , when I made the switch I checked with the Texaco Fluid tech support and also one of the chemists for Equilon who specialized in coolants and the Texaco/ Havoline/ Equilon 'experts' said that switching would be no problem.
The chemist said I was really only switching from one 95 % Ethylene Glycol coolant to another...the only difference was the Dex Cool had a much better additive package and was dyed a different color.
I followed their flushing techniques to the letter, and you wouldn't believe the problems I had.
In retrospect, I think the problems with Dex Cool seem to be that it cleans the engine / cooling system deposits ( like silicates) that the earlier coolant left on surfaces.
Those deposits wear things out, or clog them up.
Then, when the pressure caps get clogged with contaminants, air gets into the system.
The Dex Cool exposed to air breaks down, or turns acidic, or parts are left unprotected and get ruined by chemical or thermal stress.
I think the same thing happened with new cars that started with Dex Cool, but for slightly different reasons.
Either the Dex Cool lifted deposits from iron heads or blocks, or attacked solder, or compromised the radiator pressure cap.
Air was then able to either break down the Dex Cool rapidly, or make it into mud or a acid solution.
Or, maybe Dex Cool doesn't coat and protect metals exposed to air.
Maybe a little bit of silicate is needed in the formula to protect metals and gaskets?
All I know is that in some cars; Dex Cool was not a long life coolant, and it didn't protect or reduce maintenance. It did the opposite, it was a short lived, damaging coolant that needed extraordinary maintenance and service.
Dex Cool can take out water pump seals, fill overflow tanks with mud, interfere with pressure caps, and venerally clog up or damage the coolant system and gaskets.
Dex Cool deserves to be sued, and I feel bad for evey family that lost money because of this product.
I'm sure that Dex Cool can work in certain vehicles...maybe if the cooling system design agrees with it.
I also know that Dex Cool can be a source of huge problems in well maintained engines.
During my brief and ill-fated foray into GM ownership, on one of my many trips to the dealer service department, I caught a tech in a rare moment of frustration and candor. His name for the stuff: RustCool! Ouch!
Thanks for the article!quote:
Originally posted by Ray H:
Interesting article reprint on Valvoline's site about the various coolant concentrate recipes. (requires Adobe Acrobat or Acrobat Reader) Valvoline does make and market both "OAT", (officially licensed as Dex-Cool), and "HOAT", (G-05), coolants. Prestone makes officially licensed Dex-Cool coolant. ChevronTexaco (Havoline) makes officially licensed Dex-Cool coolant. What caught my attention was a statement that the "major" Asian manufacturers have adopted OAT (NOT HOAT) chemistry. Presuming both Toyota and Honda are major Asian players, isn't it interesting that red Toyota coolant concentrate and green Honda coolant concentrate are close kin to Dex-Cool? Hyundai may or may not be on this bandwagon with their green-dyed factory coolant, but given the company's penchant for mimicking their Japanese counterparts, I believe the smart money would be placed in the OAT category, too. The article also stated that solder may not be adequately protected with OAT chemistry. This would impicate older soldered radiators - meaning brass, which was retired from general OEM use around 1993. Unless I'm badly out of date, aluminum radiators are not soldered up. I believe the use of aluminum cores coincided with the introduction of crimped plastic end pieces. GM, as part of the company's ongoing "Mark of Excellence" QC program, is known to have had some serious cylinder head and intake manifold gasket issues on their pushrod V-6 engine family. The resulting leakage allowed air into the system and, according to the article, air is the kiss of death when OAT chemistry is involved -- loss of metal protection in exposed areas and resulting rapid corrosion buildup -- the old viscious cycle. So, where does all this leave Dex-Cool and other OAT chemistries? Well, with three major American coolant producers and the Asian automotive manufacturers on board, the stuff'll probably be around for a long, long, very long while. To be fair to GM, the company does have a long history of pioneering new technology. I don't fault the company for jumping onto the OAT bandwagon with both feet. They got caught up by the company bean counters putting too much reliance on a new, cost saving, but perhaps not fully explored gasket technology. (that and underestimating the American consumer's penchant for making unwarranted leaps of faith -- namely in this case that the presence of extended life coolant equates to not having to bother checking the coolant level for five years...)
I am so frustrated that Havoline Dex Cool was such a terrible product and damaged so many of the cars that I switched from Green coolant to Havoline Dex Cool.
I can't believe that Texaco / Equilon kept telling me that switching was great and problem free!
I'm hoping that the Zerex G-05 is better. Although every new car may just stick to factory fluid and never change!
I was under the impression from the article I linked to that HybridOAT coolants are the IOAT/OAT blend.
All I can tell you, is from looking at the Toyota Red label, which I have a image of somewhere around here, is that Toyota Red has both OAT and IOAT technology.
Interesting article reprint on Valvoline's site about the various coolant concentrate recipes. (requires Adobe Acrobat or Acrobat Reader) Valvoline does make and market both "OAT", (officially licensed as Dex-Cool), and "HOAT", (G-05), coolants. Prestone makes officially licensed Dex-Cool coolant. ChevronTexaco (Havoline) makes officially licensed Dex-Cool coolant. What caught my attention was a statement that the "major" Asian manufacturers have adopted OAT (NOT HOAT) chemistry. Presuming both Toyota and Honda are major Asian players, isn't it interesting that red Toyota coolant concentrate and green Honda coolant concentrate are close kin to Dex-Cool? Hyundai may or may not be on this bandwagon with their green-dyed factory coolant, but given the company's penchant for mimicking their Japanese counterparts, I believe the smart money would be placed in the OAT category, too. The article also stated that solder may not be adequately protected with OAT chemistry. This would impicate older soldered radiators - meaning brass, which was retired from general OEM use around 1993. Unless I'm badly out of date, aluminum radiators are not soldered up. I believe the use of aluminum cores coincided with the introduction of crimped plastic end pieces. GM, as part of the company's ongoing "Mark of Excellence" QC program, is known to have had some serious cylinder head and intake manifold gasket issues on their pushrod V-6 engine family. The resulting leakage allowed air into the system and, according to the article, air is the kiss of death when OAT chemistry is involved -- loss of metal protection in exposed areas and resulting rapid corrosion buildup -- the old viscious cycle. So, where does all this leave Dex-Cool and other OAT chemistries? Well, with three major American coolant producers and the Asian automotive manufacturers on board, the stuff'll probably be around for a long, long, very long while. To be fair to GM, the company does have a long history of pioneering new technology. I don't fault the company for jumping onto the OAT bandwagon with both feet. They got caught up by the company bean counters putting too much reliance on a new, cost saving, but perhaps not fully explored gasket technology. (that and underestimating the American consumer's penchant for making unwarranted leaps of faith -- namely in this case that the presence of extended life coolant equates to not having to bother checking the coolant level for five years...
)
I am currently running Dexcool in a '93 Ciera that did not come with it. I've had ZERO problems in 90k(170k total on car) there. I also ran Dexcool in my '96 Impala SS, which came with Dex as factory fill. 3 plugged heater cores, in 75k, later, I switched to Toyota Red, which is a IOAT/OAT blend and have had no more problems.
VaderSS:
< All I can tell you, is from looking at the Toyota Red label, which I have a image of somewhere around here, is that Toyota Red has both OAT and IOAT technology. >
I did a lot of research when we bought a new 2002 Toyota. My previous vehicles had been converted to DEX-COOL ('90 Honda, '90 VW - no problems at all). I found this on a UK website:
Anti-Freeze: What are the different types and properties?
There are currently five main types of antifreeze. In all cases the 'anti-freeze' properties last the life of the coolant - it is the various additives that deteriorate with time. These additives include anti-foaming agents, surfactants (to improve the 'wetting' of the coolant and hence give better heat transfer) and, most importantly, anti-corrosion additives.
As the range of alloys and plastics used in modern engines grows ever more complex it is important to ensure that the correct anti-freeze is used.
1. Ethylene Glycol - this is the traditional stuff, used since the 1950's. It uses silicates to stop corrosion by passivating the metal surface. This type of anti-freeze is suitable for most European cars, but not Japanese cars. Japanese manufacturers normally recommend a low- or no-silicate formulation due to the nature of the seal materials that they use (see below).
Typical service life of 2-4 years.
2. Ethylene Glycol: Low- or no-silicate formulation. This is specified by most Japanese cars. OEM Nissan, Toyota 'red' etc. antifreezes use phosphates rather than silicates to inhibit corrosion. Silicates are abrasive and the use of high silicate antifreezes in Japanese cars may result in premature failure of seal materials.
Typical service life of 2-4 years.
3. Mono Propylene Glycol - this still uses silicates and is claimed to last 4 years. Mono Propylene Glycol does not conduct heat as well as Ethylene Glycol and currently carries NO recommendation from any major car manufacturer- and some actually caution against it. The main claim to fame for Mono Propylene Glycol is that its less toxic than Ethylene Glycol.
Typical service life of 2-4 years.
4. Organic Acid Technology (OAT) - e.g. GM 'DexCool'. Introduced in 1995, this is a recyclable and biodegradable antifreeze which is based on organic acids and is silicate- and phosphate-free. However, due to the nature of the chemicals used, it can attack certain seal and gasket materials and therefore should only be used in vehicles for which it is factory specified.
OAT antifreeze MUST NOT be mixed with the types listed above - if you wish to switch to OAT type then the cooling system must first be chemically flushed.
The claimed service life of the corrosion inhibitor package is about 5 years, or 100-150,000 miles.
5. Ethylene Glycol-based 'Hybrid Organic Acid Technology' (HOAT). Uses Ethylene Glycol, but with OAT-based corrosion inhibitors and some added silicates; most usually BASF's "Glysantin" additive package is used (also known as 'G-05'). HOAT is less agressive than straight OAT anti-freeze and has better cavitation resistance. Again, best to thoroughly flush your system if switching to it.
Lasts 4-5 years.
The bottom line is to refill your engine with what the factory supplied and do a flush-and-refill every 4 years maximum. If you have a Japanese car, stick to the maker's brand since non-OEM coolants may contain higher levels of potentially damaging silicates.
If mixing your coolant from a 'concentrate' then use demineralised or distilled water (available from motor factors at around £3 for 5 litres) to make up the quantity - UK tap water often has a lot of dissolved minerals in it which can leave scale deposits inside the engine's coolant passages.
I was planning on moving the Toyota over to either DEX-COOL or G-05 when it came time to service it - mainly because I don't want to be hostage to Toyota Parts Division.
< All I can tell you, is from looking at the Toyota Red label, which I have a image of somewhere around here, is that Toyota Red has both OAT and IOAT technology. >
I did a lot of research when we bought a new 2002 Toyota. My previous vehicles had been converted to DEX-COOL ('90 Honda, '90 VW - no problems at all). I found this on a UK website:
Anti-Freeze: What are the different types and properties?
There are currently five main types of antifreeze. In all cases the 'anti-freeze' properties last the life of the coolant - it is the various additives that deteriorate with time. These additives include anti-foaming agents, surfactants (to improve the 'wetting' of the coolant and hence give better heat transfer) and, most importantly, anti-corrosion additives.
As the range of alloys and plastics used in modern engines grows ever more complex it is important to ensure that the correct anti-freeze is used.
1. Ethylene Glycol - this is the traditional stuff, used since the 1950's. It uses silicates to stop corrosion by passivating the metal surface. This type of anti-freeze is suitable for most European cars, but not Japanese cars. Japanese manufacturers normally recommend a low- or no-silicate formulation due to the nature of the seal materials that they use (see below).
Typical service life of 2-4 years.
2. Ethylene Glycol: Low- or no-silicate formulation. This is specified by most Japanese cars. OEM Nissan, Toyota 'red' etc. antifreezes use phosphates rather than silicates to inhibit corrosion. Silicates are abrasive and the use of high silicate antifreezes in Japanese cars may result in premature failure of seal materials.
Typical service life of 2-4 years.
3. Mono Propylene Glycol - this still uses silicates and is claimed to last 4 years. Mono Propylene Glycol does not conduct heat as well as Ethylene Glycol and currently carries NO recommendation from any major car manufacturer- and some actually caution against it. The main claim to fame for Mono Propylene Glycol is that its less toxic than Ethylene Glycol.
Typical service life of 2-4 years.
4. Organic Acid Technology (OAT) - e.g. GM 'DexCool'. Introduced in 1995, this is a recyclable and biodegradable antifreeze which is based on organic acids and is silicate- and phosphate-free. However, due to the nature of the chemicals used, it can attack certain seal and gasket materials and therefore should only be used in vehicles for which it is factory specified.
OAT antifreeze MUST NOT be mixed with the types listed above - if you wish to switch to OAT type then the cooling system must first be chemically flushed.
The claimed service life of the corrosion inhibitor package is about 5 years, or 100-150,000 miles.
5. Ethylene Glycol-based 'Hybrid Organic Acid Technology' (HOAT). Uses Ethylene Glycol, but with OAT-based corrosion inhibitors and some added silicates; most usually BASF's "Glysantin" additive package is used (also known as 'G-05'). HOAT is less agressive than straight OAT anti-freeze and has better cavitation resistance. Again, best to thoroughly flush your system if switching to it.
Lasts 4-5 years.
The bottom line is to refill your engine with what the factory supplied and do a flush-and-refill every 4 years maximum. If you have a Japanese car, stick to the maker's brand since non-OEM coolants may contain higher levels of potentially damaging silicates.
If mixing your coolant from a 'concentrate' then use demineralised or distilled water (available from motor factors at around £3 for 5 litres) to make up the quantity - UK tap water often has a lot of dissolved minerals in it which can leave scale deposits inside the engine's coolant passages.
I was planning on moving the Toyota over to either DEX-COOL or G-05 when it came time to service it - mainly because I don't want to be hostage to Toyota Parts Division.
The VW, when I sold it, had 168,000 miles on it and about 90,000 on the DEX-COOL. The radiator looked like new inside.
The Honda I'm still driving with 148,000 miles on it, with about 60,000 on the DEX-COOL. Other than a slight orange cast, the contents look like a spring-fed lake.
I did a triple-flush of both - including blocks and heater cores - when I did the changeover. This involved driving them between flushes and doing the last two flushes with plain tap water. This precluded cross-contamination from other coolant.
I also religiously top off the overflow tank, keep the systems airtight and pressure tight, and otherwise avoid the airleaks, cavitation, and other problems that seem to afflict certain GM pushrod V-6 and V8 motors.
I may have the exceptions that prove the rule, but my impression is that the problems are related to cars with other cooling system problems, problems that DEX-COOL apparently can't tolerate.
It was doing OK in my Chevy too. I switched to a Dexcool approved coolant that isn't actually Dexcool to be on the safe side though.
There usually seems to be a reason when Dexcool messes up a cooling system. I hope nothing goes a bit off with your system as long as you keep using it.
Any coolant that will trash the cooling system on an engine just because the system isn't operating exactly right is trash and should be taken off the market.
The Dexcool appoligists don't agree though. I wonder if there are any Dexcool appologists left at GM except in their legal offices?
As those of us who rodded out radiators in the 60s of cars with DOWguard, or who have had any number of other brands of ethylene glycol anti-freeze form a white impenetrable substance in the presence of hard water, overheating, or certain gasket sealers can testify, there is no coolant that won't head south if the right conditions are present.
The chemistry of the DEX-COOL makes complete sense. That's why I moved over to it. Like anything, it isn't bullet-proof. You pays your money and takes your choices.
Well said, Marty!
- Status
