Dexcool Debate

[WalterMitty]

I am puzzled by the air contact issue. A portion of the coolant is always exposed to air in the overflow tank. Some coolant is pumped into and back out of the tank with every heating/cooling cycle.

I do not understand the failure mode, can someone elaborate?

 

[G-MAN]

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I am puzzled by the air contact issue. A portion of the coolant is always exposed to air in the overflow tank. Some coolant is pumped into and back out of the tank with every heating/cooling cycle.

I do not understand the failure mode, can someone elaborate?

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Here's how I understand the Dexcool/air/crud cycle:

1. It generally only happens in engines that have iron heads.

2. If the coolant is allowed to get low, air pockets form in the coolant passages in the heads.

3. Because Dexcool has no silicates, bubbles and cavitation quickly remove the OAT coating from the exposed iron surfaces.

4. The exposed iron surfaces RUST.

5. Fresh coolant that comes in contact with the RUST washes it off.

6. This RUST mixes in with the coolant and becomes brown gloppy sludge.

 

[Ray H]

Everything you said, but aluminum cooling system components can have problems, too. Aluminum will corrode in the presense of oxygen. Air pockets will lead to cavitation damage in aluminum, too. Aluminum oxide is even more abrasive than iron rust. Aluminum oxide is better known as corundum (an industrial abrassive second only to diamond in hardness) as well as gemstones when highly purified: ruby (red) and sapphire (water white and blue).

 

[Ray H]

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...Aluminum oxide is better known as carbide (an industrial abrassive second only to diamond in hardness)...

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Whoops - that was supposed to be, "corundum.

 

[G-MAN]

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...Aluminum oxide is better known as carbide (an industrial abrassive second only to diamond in hardness)...

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Whoops - that was supposed to be, "corundum.

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I fixed it for you.

The synthetic sapphire crystals used in watches are made from corundum, as are the "rubies" used as jewel bearing surfaces in the movements.

 

[toocrazy2yoo]

How the He(( do you guys know all this?

 

[Ray H]

I used to participate on a mechanical watch forum. (None of 'em are as consistently accurate as a $5.00 quartz movement watch, but they do have "soul", and like a faithful woman, depend on you, not a battery, to keep 'em purrin'...)

 

[G-MAN]

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I used to participate on a mechanical watch forum. (None of 'em are as consistently accurate as a $5.00 quartz movement watch, but they do have "soul", and like a faithful woman, depend on you, not a battery, to keep 'em purrin'...)

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And watches are my other "hobby."

 

[Ray H]

Thanks. G-MAN, is there any reason we no longer have editing privilege within a nominal 30 minute window as before?

 

[G-MAN]

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Thanks. G-MAN, is there any reason we no longer have editing privilege within a nominal 30 minute window as before?

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No. It should work, but it doesn't.

 

[Jim 5]

G-man

These bad things that happen seem to be due to air pockets developing in those locations from an inproperly purged (or low on coolant) cooling system.

I had two questions arising from this:

1. How do you properly purge a GM v8 engine (the 5.3L variety) to ensure there's no air pockets after a coolant change? I don't see a traditional screw in the thermostat body, and that body seems relatively low on the engine;

2. My truck is 2.5 years old with 48k miles. Am I wasting my time changing out the dexcool now? Will I still have a good margin of safety waiting to ~3.5 years and 53k miles? I have all the service records for this truck, and as far as I can see, no coolant has been added. It is always at the full point in the reservoir and UOA shows no Na or K.


Thanks in advance for anyone's thoughts!

 

[Auto-Union]

Let's take the informed common-sense approach to DexCool and ask why mfgs are RUNNING away from it. Audi/VW saw a need to change their OAT-based G-12 to G-12 Plus. Whatever it consists of...I dunno. Last time I chimed-in here, Dex was on it's way OUT.

 

[MarkC]

It still seems to be here.

 

[BuzzCut]

I haven't seen manufacturers running away as you stated... Please show some more factual data instead of opinions.

 

[Auto-Union]

Umm, I'm going from neither "data" or opinion, but from memory. Have you anything to add?

 

[G-MAN]

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Umm, I'm going from neither "data" or opinion, but from memory. Have you anything to add?

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How about telling us which manufacturers you "remember" that are running away from Dex-Cool.

 

[Auto-Union]

Not really worth the effort.

 

[BuzzCut]

Once again when the haters are cornered they run away...very interesting

 

[Auto-Union]

Cornered by someone with nothing to offer to the discussion? I don't think so. I actually have other things to do than research YOUR questions, and rely on some of the expert knowledge here to fill in the blanks. Where is your list of mfgs and their corresponding coolants? I'm waiting.
Here are a few mfgs using G-05, afaik.
BMW, Mercedes, Chrysler, John Deere, and possibly Ford. I'm sure there are others, but I don't care aboput it enough to search. VW switched away from their G-12 OAT coolant. If GM sticking with Dexcool makes you really happy, (apparently it does) good for you.

 

[Auto-Union]

Yeah, I just had the pleasure of reviewing BuzzCut's posts on the subject of coolants. Not only are they obnoxious, he has nothing to offer other than to challenge anybody and everyone to "post data". Sorry Mr.Troll...you know where to go bite.