Dex-cool

[Robert C.]

Is Dex-cool just regular anti-freeze or ? Does it lower operating temps.?What's the difference?

[Michael Hampson]

Re: Dex-cool

Bob, there's a whole slew of Dexcool postings about 20 messages down, that are pretty helpful, if you haven't looked yet...

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[Duke W.]

Re: Dex-cool

Like conventional antifreeze, Dexcool is an ethylene glycol based product, but it uses a completely different corrosion inhibitor technology based on organic carboxylates rather than inorganic salts. Extensive testing by GM, Texaco, and several HD diesel engine manufacturers has shown that Dexcool provides superior corrosion protection, particularly for aluminum, even with extended change intervals. GM (except Saturn) went to Dexcool across the board in 1994 or 1995 and recommends a change interval of five years or 150,000 miles. Prior to that they used conventional ethylene glycol based antifreeze with a conventional inorganic salt inhibitor package and the change interval was two years or 30,000 miles

Duke

[Jimmy G.]

Re: Dex-cool

My opinion is that Dex - Cool sucks. I had a plugged heater and rad. core in a 1996 SS Impala thanks to the inhibitor package plating out on the fins. My dealer said they had tons of problems with it and strongly recommended I "flush" it. I did and no problems so far. I recommend going conventional coolant.

[Brian M.]

Re: Dex-cool

I believe that the factory also added sealing pellets that caused the cloging in the Impala's. I just flushed mine (96 with 27000 miles 12/96 car) and re-filled with 50/50 dex-cool and water from my dehumidifier. The waterfall sound ig gone and the heat is much better. I believe in Dex-Cool. NOT the sealing pellets.

[Duke W.]

Dexcool flack

There are a lot of anecdotal stories and flack on the internet about Dexcool. The major OEMs have addressed two specific issues. GM wrote a technical service bulletin (99-06-02-12, 28 May 1999), which specifically addresses problems with the 4.3L V-6 used on S-10s and their SUV derivatives. The following is a quote:

"Vehicles equipped with Dexcool coolant, which may have been operated for extended periods of time with low coolant level (usually in excees of 20,000 miles, may be suseptible to the formation of rust like material in the cooling system."

There is also an issue with the HD version of this product (which is not called Dexcool) used in HD diesel engines. It is similar in chemistry, but has some differences to address specific HD diesel engine issues, primarily liner cavitation erosion. Texaco and Cummins briefly got into a public flame throwing contest over premature failure of a silicone seal in the cooling system on an old design engine, but they are now working together to solve this problem. I mention this only for reference.

The world is full of anecdotes and war stories, but they rarely make good science. There are many laboratory tests that show Dexcool to be significntly superior to conventional antifreeze with inorganic salt corrosion inhibitor packages, and this is backed up by millions of miles of fleet tests overseen by the OEM engine manufacturers and suppliers. Also, it is backed by GM's basic and extended warranties for extended change intervals. I don't know about the Impala SS problem or why they would add sealing pellets. Sometimes it's nearly impossible to get the real story. I personally believe in the efficacy and integrity of the industy tests. and I continue to use Dexcool in all my vehicles and highly recommend it to others.

Duke

[Jeff]

Sometimes Dexcool does suck.

I have put three radiators in my 94 S-10 4.3 within 100,000 miles (which is two more radiators than I have put in everything else I've ever owned). The rust was unbelievable and unflushable. Before the third radiator, I finally flushed it for 3 straight days (yup, just left it running day and night with the garden hose hooked to the (old) radiator neck from my shop hot water heater. FWIW, it uses about 1/2gph at idle). No problems since I switched away from Dexcool. My 98 K3500 leaks the stuff and I can't seem to find out where it's going. Same deal as the S-10, inside the radiator looks like ****. If that doesn't mean it sucks, what would? I am afraid to even open the radiator on my 99 C5 and look inside, so I decided to just trade it on a Z06 and may drain the Dexcool upon taking delivery.

JP

[Dale Pearman]

Re: Dexcool flack

I like Prestone!

Varooom!

[mike hom]

Re: dehumidifier water?????????

What's up with that?

[Brian M.]

Re: dehumidifier water?????????

Home Made Distilled