The Use Of Ethylene Glycol In Our Radiators

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SnowDrifter

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That article is outright wrong. Dexcool uses EG rather than PG as per on the MSDS.

I'd caution anyone from using PG in their vehicle unless they know damn well what they're doing. Higher viscosty and specific gravity put you at a higher risk for water pump cavitation. And PG doesn't play nice with neoprene, which is sometimes used in gaskets and radiator hoses.



The thing with dexcool(and other OATs) is: It doesn't play nice with nylon. You know, the heater core fittings, radiator end caps, plastic housed gaskets. The things GM likes to use.... The additives in it also don't respond well to air exposure or other coolants, leading to the nasty gelling you see from time to time. And when it breaks down, it turns VERY acidic VERY quickly.



FWIW I have some maintenance coming up on my vehicle and will be switching out to second gen honda coolant. Did a lot of homework on coolant formulations and interactions and came to the conclusion it's the safest.

As always, do your own research. Don't take my advice. I'm just some guy on the internet.
 

BG1988

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I have seen several posts as of late of folks replacing propylene glycol (Dexcool) with the older ethylene glycol.

We should discourage folks from making this switch as I believe it is a mistake.

https://www.hemmings.com/blog/2014/08/01/tech-101-the-colors-of-antifreeze/

Not mentioned in the article is the boiling point of the two coolants. Ethylene Glycol (green) has a boiling point when mixed 50/50 with water of 250 degrees.

Propylene Glycol (Dexcool) has a boiling point when mixed 50/50 with water of 265 degrees.

GM introduced Dexcool in 1995 and has redesigned the cooling systems to take advantage of this coolant and takes the higher boiling point into consideration in computer programming and engine design.

Nuggets from the article:
1. Lasts longer
2. Friendly with aluminum radiators and heads
3. Not so friendly with copper radiators and lead solder
4. Hoses last longer, see ECD in the article
5. Ecologically friendly

Many of the horror stories attributed to Dexcool stem from ignorance. Folks topping off their Dexcool equipped vehicle's radiator with ethelyne glycol or too much water over time ruining its 50/50 balance which lowers the boiling point and longevity of the fluid. Not to mention creating that awful sludge that clogs the coolant passages in the block and radiator core.

Mine own experience with Dexcool vehicles has been positive. Most of the cars have had zero cooling system issues or needed maintenance over the last 20+ years, not even a radiator hose.

Remember all the radiator hoses we changed when we ran the green stuff? Comments?
the sludge was caused by sealant tablets dealers used
 

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That article is outright wrong. Dexcool uses EG rather than PG as per on the MSDS.

I'd caution anyone from using PG in their vehicle unless they know damn well what they're doing. Higher viscosty and specific gravity put you at a higher risk for water pump cavitation. And PG doesn't play nice with neoprene, which is sometimes used in gaskets and radiator hoses.



The thing with dexcool(and other OATs) is: It doesn't play nice with nylon. You know, the heater core fittings, radiator end caps, plastic housed gaskets. The things GM likes to use.... The additives in it also don't respond well to air exposure or other coolants, leading to the nasty gelling you see from time to time. And when it breaks down, it turns VERY acidic VERY quickly.



FWIW I have some maintenance coming up on my vehicle and will be switching out to second gen honda coolant. Did a lot of homework on coolant formulations and interactions and came to the conclusion it's the safest.

As always, do your own research. Don't take my advice. I'm just some guy on the internet.


Where do you get that information? Quote:Organic Acid Technology or OAT: Commonly referred in GM vehicles as Dex-Cool or to other manufacturers, propylene glycol. GM introduced Dex-Cool in 1995. ... It is made from a propylene glycol base, which makes it less poisonous than conventional IAT for children and pets.Aug 1, 2014.

I’m pretty sure if Dex-Cool harms the plastic that GM uses in the cooling system they wouldn’t be using it. I mean, it’s their formulation. Made for their vehicles that they warranty.
 

SnowDrifter

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Rocket Man

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Right from the horse's mouth:
http://www.worldpac.com/tagged/ACD_Dexcool_10-101_EN.pdf

The MSDS for dexcool indicates EG is used, NOT PG

View attachment 217144

You'll also note one of the ingredients in there, ethyl hexanoic acid. It's a plasticizer and attacks nylon and silicone. There was a big lawsuit about it in '08
That’s not what I read everywhere I look. I’ve had Dexcool in my GM vehicles for many many years and they’re doing fine thank you. I’ll stick with it. Never heard about that lawsuit but nothing must have come of it or I’m sure we all would have. Hey James @swathd
iver
what have you to say about all this? You started this thread after all, time to come back and enlighten us with your vast knowledge brother.

Edit :I see different terms being used to describe it, with the only thing that seems to stay the same is the fact that Dex is Organic Acid Technology and normal Ethylene Glycol is Inorganic Acid Technology. There’s definitely something that makes Dex different than normal stuff and they’re not saying what it is. Anyway like I said, I’ll stick with it.
 
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SnowDrifter

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Never heard about that lawsuit but nothing must have come of it or I’m sure we all would have.
It was a 150 million suit which GM lost.
https://www.reuters.com/article/gm-...engine-coolant-problems-idUSN2735011520080327


That’s not what I read everywhere I look
Read what?



I feel like we're playing this odd game where you say you've not heard of it, so I go to google and post links on publicly available info. What's up?
 

Rocket Man

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It was a 150 million suit which GM lost.
https://www.reuters.com/article/gm-...engine-coolant-problems-idUSN2735011520080327



Read what?



I feel like we're playing this odd game where you say you've not heard of it, so I go to google and post links on publicly available info. What's up?
Nothings up, not trying to say you’re right or wrong. I see you’ve delved into this and have a strong opinion. The lawsuit you quoted is old, 11 years old to be exact, and they never admitted any wrongdoing. They settled to make it go away like a lot of class actions. I remember a long time ago there were a few problems but mostly due to improper use. The issue you stated with damaging the plastics that are part of the cooling system doesn’t make sense to me, and if it doesn’t make sense it’s usually not true. I do not believe they would purposely try to sabotage their own vehicles. And the part about it being based on ethylene glycol apparently is true according to the MSDS but not according to many other sources, but that doesn’t matter to me anyway. The stuff is the recommended coolant for GM vehicles, it works great, and I trust it. Never had a problem with it. It has haters that’s for sure, but there’s always another side to every opinion. Just trying to show a different opinion and different facts that’s all. Don’t get your feathers ruffled, like I said Im not out to prove you wrong on any count or tell people what to use or not to use. We’re both just guys on the internet, not experts. Take no offense.
 

SnowDrifter

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Nothing's ruffled. Just being direct in questioning :) If I were upset, you'd know.


I don't think we can discount something 11 years old given the age of our vehicles. That puts them around the same time frame. Even if you want to account for different formulations, the MSDS still indicates the same additives used as were causing the issues.

As to the article: That's the only one I can find that mentioned PG being used in dexcool. The MSDS as well as third party info indicates it's all EG based. Plus PG based coolant has a fairly short service life, which based on the service interval, also doesn't support it. Honestly I'm unconvinced. If you've found other info I'd like to see it. If we can't come to an agreement on it I can send GM an email inquiring for info.


For the ethylhexanoic acid: Don't really know what to say other than it's true. I wouldn't call it sabotage, more a cost/risk assessment coupled with the technology of the time. Dexcool was an early LL coolant intended for use with aluminum parts like the cylinder heads. Our vehicles are long lived, well beyond what I'd consider a typical ownership cycle. We have the opportunity to see the long term effects of additives and formulations that under a typical use case scenario, would never be an issue.

I'm of the opinion that there are better coolant formulation than dexcool available now. I think it's important to bear in mind a relevance to the time. PHOAT coolants didn't come on the market until the 2002 range, after our body style was released. I know GM still uses dexcool today, so I'm wondering if they changed up the plastics they use? Or if they've determined that the decrease in component lifespan is still long enough to meet whatever ownership timeframe they've determined to be the life of the vehicle
 

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