GM Dexcool Coolant / Antifreeze

Subject: Re: GM Dexcool Coolant / Antifreeze Mon Nov 02, 2009 9:23 am

Quote:

I thought Dexcool was pink and regular antifreeze green, someone may have topped my system off and mixed the two because it's brown now and I have to do something before winter. I'm going to flush and re-fill with Regular (green) antifreeze since it's something I prefer to do every couple years and the only good thing I've heard about the dexcool is that it does'nt kill the neighborhood cats. Will I have to change my hoses too? What problems might I encounter by switching from pink to green.
I'm thinking GM pushes the pink because they probably go through hundreds of thousands of gallons a year and care more about their EPA status than they do the consumer...could be wrong.

DexCool is typically orange in color. It will kill the neighborhood cats because it's an ethylene glycol antifreeze, just like the old green stuff. DexCool is actually a superior formula to the green stuff, so it lasts a much longer time. If you change back to the green, be sure and flush it every year or so, or at least test it to see if it's still working.

There is a debate on mixing DexCool and the old green formula, that it will create a gel or sludge in the cooling system - from what I've read, this is false, purely automotive folklore. If you mix the two, they will create a brown color, unappealing to most, but it is not going to damage your cooling system. The two formulas are different, but they are similar in that they are both ethylene glycol. You will not hurt anything by mixing the two.

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Subject: Re: GM Dexcool Coolant / Antifreeze Mon Nov 02, 2009 1:38 pm

My understanding in talking w/ an auto tech is exactly as Aaron is stating.

And, this is the rule I've always followed:
If your car has always had orange then the time between flushes is much longer (50K miles or 5 years). If your car has always had green, or changed from green to orange, or changed from orange to green, then you need to flush every 2 years regardless of mileage and regardless of what color antifreeze you now put in.

My 2 Eldo's came from the factory w/ orange and I've flushed them once...their temps have always been spot-on. Since I don't know what the previous owners might have done, my 2 Riv's have green and I flush them every two years...their temps remain spot-on also.

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Subject: Re: GM Dexcool Coolant / Antifreeze Mon Nov 02, 2009 6:14 pm

While it doesn't cause sludge like the rumors claim mixing the two it does reduce its efficiency and life span.

Quote:

There are rumors that mixing DEX-COOL with standard green (non-OAT) coolant causes a chemical reaction that produces sludge in the cooling system. According to the DEX-COOL manufacturer, however, "mixing a 'green' [non-OAT] coolant with DEX-COOL reduces the batch’s change interval to 2 years or 30,000 miles, but will otherwise cause no damage to the engine."[10]

According to Wikipedia
http://en.wikipedia.org/wiki/Antifreeze

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Subject: Re: GM Dexcool Coolant / Antifreeze Mon Nov 02, 2009 6:26 pm

Well sure, if you dilute the 5 year antifreeze with 2 year antifreeze, you're going have some compromise. Imo, the only reason not to use DexCool is the LIM gasket issue, which should be fixed around 150k miles. Then keep using DexCool and enjoy 5 year change intervals.

If you dilute with green, or switch to all green, then you have 2 year change intervals, or one year intervals in my case, putting 30k miles on per year.

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Subject: Re: GM Dexcool Coolant / Antifreeze Mon Nov 02, 2009 6:34 pm

I'm not trying to dispute anything you've said AA, simply trying to add sources for even more credibility.

If its been mixed and the car is new to you, its good insurance to have the system flushed by a radiator shop and refilled with your choice of coolant. Since you can't be sure of how long its been in there. Just my 0.02

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-Nate-
:Proud owner of:
1996 Buick Riviera S/C- Gutted Air box, Autolite AP605 - Daily Driver
1973 Chevrolet C/10 Cheyenne Super 454/TH350 - ALL FEAR THE PORCUPINE

Subject: Re: GM Dexcool Coolant / Antifreeze Mon Nov 02, 2009 6:37 pm

Likewise, I wasn't disputing your info, just clarifying that the green stuff only decreases the lifespan of DexCool because it has a shorter lifespan itself. Worst case, you end up as if you ran all green, but not worse.

I agree, it's a good idea to flush and change when you don't know how long it's been in there, no matter what type of coolant it is.

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Subject: Re: GM Dexcool Coolant / Antifreeze Mon Nov 02, 2009 6:39 pm

Bringing up a discussion on Dex-Cool is like discussing Politics or Religion. Maybe it should be banned.....j/k

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Subject: Re: GM Dexcool Coolant / Antifreeze Sat Nov 14, 2009 7:29 pm

I bought 3 containers of the 50/50 Dex-Cool today. Is that enough?

Subject: Re: GM Dexcool Coolant / Antifreeze Sat Nov 14, 2009 7:47 pm

Jack the R wrote:

I bought 3 containers of the 50/50 Dex-Cool today. Is that enough?

13 qts is system capacity, so you are 1 qt. short, no big deal.

Subject: Re: GM Dexcool Coolant / Antifreeze Sat Nov 14, 2009 9:28 pm

I've got an open jug of 100% from a few year's back. I'll top it off with that. Thanks.