As long as I can remember, they, being the dealership, and others, and the manual I think too, says to ONLY use GM Dexcool, and not the regular Prestone antifreeze stuff.
Two questions, please:
a. Have ordered a new 2009 Buick LaCrosse.
Can I use up the Dexcool that I still have in the new car ?
b. Does the new car still require this GM Dexcool, or can I use the regular Prestone in it ?
BTW: What made the Dexcool so "unique," or is/was it just a marketing ploy ?
I thought GM was having problems with the dexcool clogging/corroding up the cooling system or something like that..
I've also been told you can flush the dexcool and put regular stuff in, but you can't go the other way.
************** All the antifreeze brands that I have seen lately in FLAPS and WalMart, etc, claim to be fully compatible with DexCool.
In either case, if you flush the engine and radiator properly, you can go either way.
DexCool was not, IMO, all that it was made out to be, a superior product. It was based on organic acid technology and low or no silicate. Should have been better environmentally, was different, was marketed rigidly.
You CAN run regular old silicate antifreeze in any engine... but a) you have to change it on the shorter schedule, not the extended life schedule and b) the silicates may drastically shorten the life of new waterpump seals.
Its a silicate-free organic acid technology antifreeze. Its not just a marketing ploy. The basic coolant is still ethylene glycol, just like regular old green antifreeze, but the anti-corrosion package is completely different. It uses organic acids to inhibit corrosion and has no silicates or phosphates. Its proven to be pretty lousy stuff in practice because more engine bits and pieces had to be changed to really be compatible with it than GM anticipated. GM's own "compatible" engines had huge problems early on, but newer GM engines really do seem to be truly compatible.
A much saner approach is G-05 antifreeze used by Chrysler, Ford, many diesel engine manufacturers, and many european carmakers. Its what is called a "hybrid organic acid technology" antifreeze. While it has far fewer silicates than traditional green antifreeze, it still has some silicates and in practice its proving to be 100% backward-compatible with old engines made for silicate antifreeze. That is something that is absolutely NOT true of DexCool, which tends to destroy any copper-containing component like older heater cores and many head gaskets. It does have the same extended life (5 year) that DexCool has.
I agree, mostly. The HOAT technology is an improvement over the OAT. Silicate is needed, still, for protection of aluminum alloys. The Organic Acid Technology just couldnt bridge that gap.
ALL inorganic silicate has some degree of decomposition to silicic acid or gels of silica over time. It cannot, with present technology, be stopped totally. However, usually it will not cause big problems in a well formulated product. Silica is not, as some say, sand Fumed silica is actually used to formulate greases, so it does not automatically follow that silicates will cause undue wear or erosion. They CAN, in extreme cases, fill your radiator with an insoluble mineral scale. Note again, properly formulated and maintained coolant systems generally have no problem.
Copper and brass corrosion in the older formulations was inhibited by tolyltriazole, benzotriazole, or mercaptobenzothiazole. Those materials did their jobs well, but were perhaps not environmentally desirable.
I would certainly stick away from DexCool, unless I had to use it to keep a warranty alive. Then, when the car was out of warranty, I would use something that works better.
Very true, but the most by-product of degrading silicate corrosion inhibitors in cooling systems is abrasive. Its not necessarily going to happen, but it could... and I suspect that GM (and others) are scrimping on waterpump seals a bit compared to the old designs that were intended to live in an environment where silicate precipitation was more or less expected. I'd still ditch DexCool in a heartbeat, but when giving that advice to others I feel like I need to include a 'caveat emptor.' :-)
But The latest version of Prestone is a bastardized allegedly DexCool compatible mix of who-knows-what. I wouldn't put it in a Yugo. Which is why I either buy G-05 (usually Zerex's formula) or one of the generic coolants made by Old World Industries (NAPA, O'Reilly, Pep Boys, and others house brand coolants). OWI is the parent company of Peak Antifreeze, but Peak's own name-branded coolant is, like Prestone, an allegedly universal brew of crap. The coolant they make for the parts-store house brands is still a true silicate-based coolant.
to the class action settlement reached with General Motors in the GM/Dex-Cool class action lawsuit. This settlement affects people who purchased or leased a "covered vehicle" anywhere in the United States other than Missouri. A separate settlement has been reached for those who purchased or leased their vehicle in Missouri, which will offer the same benefits but will be separately approved by a Missouri court.
were factory-filled with "Dex-Cool" coolant. In summary, the lawsuits alleged that Dex-Cool degraded certain vehicles? intake manifold gaskets and other engine sealability components, and that in certain other vehicles, Dex-Cool formed a rusty sludge, clogging the vehicles? cooling systems and causing vehicles to overheat.
I've been for a long time in a 1993 Ford and a 1986 Toyota, mostly the Chevron/Texaco Havoline brand, which is identical to GM's formulation, not the Prestone stuff that's claimed to be kinder and gentler to the materials found in older cooling systems, like radiator solder and brass. If a car maker recommends a certain type of antifreeze, that's what I'd use because then if a cooling system problem develops you're more likely to get it covered under warranty or even after warranty.
Dex-cool is silicate-free and phosphate-free, and AFAIK the only other coolant like this on the retail shelves is Prestone Extended Life, which Prestone says can be used in any car. I think it's sort of like G-05, but that does contain silicate.
Exactly my feeling.. When the warranty is up, you can use something better. The old formulas were quite good, really. All of them work better if you start with a clean system and distilled or deionized water (just to keep the trace ions like magnesium, chloride, sodium, iron, low. Some of these constituents can and will react with some antifreeze components)
Phosphate free is, for the most part, not something most of us really get our panties in a knot about. Silicate has its plusses and minuses, but when properly formulated and maintained, it is about the only thing around that gives reasonable protection to aluminum.
In some older cooling systems you MUST have a silicate AF to protect the water pump impelled. No silicate and the impeller gets eaten away by cavitation. It's hard to go wrong with the old "green" stuff, at least in older cars.
Silicone antifoams are one thing, inorganic silicates for aluminum protection are another. Silicone antifoams are hard to beat when the chips are down.
The block polyols (like the BASF L61) are interesting in that they have a cloud point (above a certain temperature, these polyols come out of solution and begin to act a little like oil dispersions) which allows them to function as lubricants to some degree. They dont attack the rubber of the hoses, and double as antifoams.
Honestly, I havent checked it out to see if it has been reformulated. It takes a fair amount of instrumentation and research expense to break these down, and it has not been a matter of interest lately.
We used to buy an OAT concentrate from the manufacturer/patentor and use it in glycol blends. We did it because the client wanted this type material, and because it put us in the clear on patents. A marriage of convenience, you might say...
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