prestone / GM dealer dex-cool mix

[JHZR2]

Hi,

I asked a question along these lines about different dex-cool chemistries as a primary one for real flushing and service... but what about mixing them in intermediate service?

If I use silver bottle prestone "GM APPROVED" dex-cool, what about mixing it and GM OE dexcool that the dealer puts in during service? Since there may be some different in chemistry, and dex cool is very sensitive, is there a danger? Everything used would carry the GM 6644M approval or whatever the dex cool approval is.

Am I ok to, say, drain the radiator of the GM OE dealer installed coolant, and refill with prestone dex-cool, and still have REAL 5/150 protection? With all the fears of dexcool sludge, gaskets, water pumps, etc... is it OK to mix different OAT silicate free "dex cool" versions in the system without flushing and refilling all of it?

Is there a place to get shell dex-cool other than the dealer, since shell apparently packages it for GM? seems harder to find than even texaco.

Thanks,

JMH

 

[obbop]

I'm still trying to discover what the "Dex" stands for.

Thought it might be a slang-type name akin to "Tex" but with a "D" vice the "T" with the "D" standing for Detroit.... or sumpthin'.

More pondering.

Incessant pondering.

Yep.

 

[Matt89]

I have no technical expertise to back this up...but given two things:

1) The Prestone version is licensed "Dex Cool"

2) Prestone claims that another of their long life coolants (the new yellow stuff) can mix with any other long-life coolant with no loss of protection

I'd say you are good to go. The problems that have arisen with Dexcool have been air instrusion / vehicle design problems...not the coolant itself running out of mojo.

I've put my money where my mouth is on this by mixing coolants, hasn't been long enough to tell yet.

 

[XS650]

quote:

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Originally posted by Matt89:

I'd say you are good to go. The problems that have arisen with Dexcool have been air instrusion / vehicle design problems...not the coolant itself running out of mojo.

---

It's a coolant that turns to doo-doo when a little air gets mixed in. Cooling systems aren't perfect, cooling systems get poor maintenance, Dexcool disgraces itself more than other coolants. Dexcool -is- the problem.

Why do people keep appologizing for a mediocre product?

 

[Matt89]

quote:

---

Originally posted by XS650:

quote:

---

Originally posted by Matt89:

I'd say you are good to go. The problems that have arisen with Dexcool have been air instrusion / vehicle design problems...not the coolant itself running out of mojo.

---

It's a coolant that turns to doo-doo when a little air gets mixed in. Cooling systems aren't perfect, cooling systems get poor maintenance, Dexcool disgraces itself more than other coolants. Dexcool -is- the problem.

Why do people keep appologizing for a mediocre product?

---

Oh, believe me I'm no apologist. My point was (in answer to the original poster's question) that the problems people have had with the DexCool were not caused by the coolant losing its anticorrosion properties (other than turning to mud of course

) or some kind of 'clash' caused by mixing two different brands. As you said it was that air got in the system and caused the coolant to degrade. Either way it's not going to matter if JHZR2 mixes two types of Dexcool. If anything, switching away from the Texaco product may avoid some of the issues that were caused by the original Dexcool chemistry.

 

[JHZR2]

just a dumb question to enter here.

Apparentlyt the mixing of green and red coolant caused all sorts of issues without having air come in. Unrelated to my situation for sure, but it was along those lines, on a lesser level (as some additives between the two are different) that I was concerned...

Thanks!

JMH

 

[Ray H]

I believe both Prestone extended-life antifreeze/coolants state on their respective jugs that they can be mixed with any other extended-life antifreeze/coolant without jeopardizing the extended-life properties of either. The exception occurs when extended-life non-hybrid OAT products such as DEX-COOL and its clones are mixed with conventional coolant - the working life is reduced to the remaining working life of the conventional coolant.

 

[Dominic]

I have continuously drained/refilled mine with 50/50 dexcool. I tend to do a radiator drain/fill on an annual basis to keep the additive pack good and to flush out anything that might've built up. As a result, my coolant is always in outstanding condition.

5yr/150K? maybe. I don't trust it when I can spend less than $10/yr to keep peace of mind.

 

[JHZR2]

Ray,

What is claimed and is reality might be different in a mode detailed analysis.

We talk about oil additive clash on here sometimes... despite modern oils almost always saying theyre compatible with any other motor oil.

JMH