Coolant misinformation from a bitter grease-monkey

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Originally Posted By: mechanicx
I tend to think Texaco might have added another OA to their dexcool to improve it. But my understanding is that carboxylate acids include 2-EHA, and I think all Dexcool/Dexclones contain 2-EHA. While I think a Dexcool licenses products is a spec more than a specific formula, still as far as I know they all contain 2-EHA and that's what makes them Dexcool.

Lol Overk1ll you are using a GM type coolant in a Ford
grin2.gif
.


Possibly, and now I'm scared, LOL!
 
Originally Posted By: onion
I use G05 in my GM vehicles- which works fine despite not being the 'correct' chemistry.


I was about to switch to this as well.
But an Ashland/Valvoline/Zerex engineer I called about this very topic was VERY stern about NOT doing this due to much higher silcate levels in the G05 (or so he said).
 
So is Zerex position to stick with their licensed Dexcool product for GM vehicles? The silicates is one reason I'm not a big fan of G-05, but I don't personally think it should be a huge issue since a lot of people seemed to get away with using green.

I messaged Zerex in regards to Dexcool and gasket compatibility issues and never got a reply.
 
Originally Posted By: mechanicx
So is Zerex position to stick with their licensed Dexcool product for GM vehicles? The silicates is one reason I'm not a big fan of G-05, but I don't personally think it should be a huge issue since a lot of people seemed to get away with using green.

I messaged Zerex in regards to Dexcool and gasket compatibility issues and never got a reply.


Yes, it is their position on this subject, and YES the said engineer was informed that my car is L-O-N-G out of any form of a warranty.
So what other motavation would he have had since his company is the ONLY one making G-05, and MANY others make various forms of Dex Cool. He risked the potential for a surefire sale.
He did state that Zerex's Dex Cool formula was superior to others' which most would write off as marketing hype, but your research (on the other thread) seems to confirm this engineer's claim.
 
Originally Posted By: OVERK1LL
Originally Posted By: mechanicx
I tend to think Texaco might have added another OA to their dexcool to improve it. But my understanding is that carboxylate acids include 2-EHA, and I think all Dexcool/Dexclones contain 2-EHA. While I think a Dexcool licenses products is a spec more than a specific formula, still as far as I know they all contain 2-EHA and that's what makes them Dexcool.

Lol Overk1ll you are using a GM type coolant in a Ford
grin2.gif
.


Possibly, and now I'm scared, LOL!


It's probably going to get piston slap and your intake gaskets will melt!
 
Originally Posted By: Drew99GT
Originally Posted By: OVERK1LL
Originally Posted By: mechanicx
I tend to think Texaco might have added another OA to their dexcool to improve it. But my understanding is that carboxylate acids include 2-EHA, and I think all Dexcool/Dexclones contain 2-EHA. While I think a Dexcool licenses products is a spec more than a specific formula, still as far as I know they all contain 2-EHA and that's what makes them Dexcool.

Lol Overk1ll you are using a GM type coolant in a Ford
grin2.gif
.


Possibly, and now I'm scared, LOL!


It's probably going to get piston slap and your intake gaskets will melt!


Mother of God, all the Delvac 1 and Redline in the world aren't going to save me from this!
 
onion:

Your honesty concerning Dexcool is most refreshing and appreciated. As you know, I too have been a ardent Dex-hater and although I would never use it my vehicles, I did notice several interesting statements by Cummins in your links. Here are their quotes:

"Frequently Asked Questions About Texaco's Extended-Life Coolant Written and distributed by Cummins Engine Company"

"Do all OAT coolants have this problem?"

"No, not all OAT coolants attack silicone seals. However, we do know that this problem is caused by ethyl-hexanoic acid, the main organic acid in Texaco Extended-Life coolant. Additional commercial, as well as experimental, OAT coolants are being screened to see if other organic acid inhibitors affect silicone seals."

"Why isn't Cummins redesigning the engine to work with this coolant?"

"The redesign would take considerable time and resources. Cummins' position is that the coolant should be reformulated such that it does not adversely affect engine components. The expectation of the industry is that coolants and lubricating oils will be formulated so that they are compatible with currently available engines."

So, let me see if I can summerize their statements:

1. The Texaco ELC coolant did contain 2-EHA, and it did attack all gaskets that contained silicone including head gaskets. and it wasn't just confined to GM IM gaskets.
2. Chrysler and Ford also experienced the same problems with this 2-EHA product.
3. The coolant caused the problems, but should have been compatible with existing engine designs and materials and engines and components shouldn't need to be redesigned to work with 2-EHA coolants. GM shouldn't have needed to redesign their gaskets and engines to work with 2-EHA coolant if it had been properly formulated.
4. Cummins had many engineers study this problem and they concluded that this Texaco ELC coolant was deficient.

Therefore, this just reinforces my (and your) stance on the inferiority of all 2-EHA containing coolants (especially Dexcool) compared to alternative coolants (G-05) on the market.
 
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This is very interesting info! Makes me scratch my head at why GM has continued with Dexcool. With the way they are designing cooling system in their late model engines - no more wet intake manifolds on many engines, metal framed intake gaskets on engines with coolant running through the intake, and placing the radiator filler neck/cap at a very high point on the engine, they had to have know about these issues.
 
Originally Posted By: Drew99GT
This is very interesting info! Makes me scratch my head at why GM has continued with Dexcool. With the way they are designing cooling system in their late model engines - no more wet intake manifolds on many engines, metal framed intake gaskets on engines with coolant running through the intake, and placing the radiator filler neck/cap at a very high point on the engine, they had to have know about these issues.


That's why they are now Goverment Motors!
 
Originally Posted By: dailydriver
Originally Posted By: mechanicx
So is Zerex position to stick with their licensed Dexcool product for GM vehicles? The silicates is one reason I'm not a big fan of G-05, but I don't personally think it should be a huge issue since a lot of people seemed to get away with using green.

I messaged Zerex in regards to Dexcool and gasket compatibility issues and never got a reply.


Yes, it is their position on this subject, and YES the said engineer was informed that my car is L-O-N-G out of any form of a warranty.
So what other motavation would he have had since his company is the ONLY one making G-05, and MANY others make various forms of Dex Cool. He risked the potential for a surefire sale.
He did state that Zerex's Dex Cool formula was superior to others' which most would write off as marketing hype, but your research (on the other thread) seems to confirm this engineer's claim.


This is intresting. So how many companies will the Dexcool haters have to throw under the bus, GM, Texaco, Valvoline, Peak, Honeywell, Cummins etc?
 
I would add that I'm not a Dexcool cheerleader. So if I should find out that Dexcool also deterioates headgaskets commonly used, then I might consider it dexcool the devil. Some of the GM Dexcool applications seemed to have higher HG failure but I'm not sure if it was because of gasket material incompatibility or some other reason(s).
 
Originally Posted By: PT1
if you don't change out coolant as part of a PM program...you will have problems with ANY coolant.


So is your cooling system PM set @ 5y/150kmiles? That's allegedly the longevity of Dexcool.

Which, if you're not going to take advantage of ..what's the point in using it?
 
Originally Posted By: mechanicx
Originally Posted By: dailydriver
Originally Posted By: mechanicx
So is Zerex position to stick with their licensed Dexcool product for GM vehicles? The silicates is one reason I'm not a big fan of G-05, but I don't personally think it should be a huge issue since a lot of people seemed to get away with using green.

I messaged Zerex in regards to Dexcool and gasket compatibility issues and never got a reply.


Yes, it is their position on this subject, and YES the said engineer was informed that my car is L-O-N-G out of any form of a warranty.
So what other motavation would he have had since his company is the ONLY one making G-05, and MANY others make various forms of Dex Cool. He risked the potential for a surefire sale.
He did state that Zerex's Dex Cool formula was superior to others' which most would write off as marketing hype, but your research (on the other thread) seems to confirm this engineer's claim.


This is intresting. So how many companies will the Dexcool haters have to throw under the bus, GM, Texaco, Valvoline, Peak, Honeywell, Cummins etc?


mechanicx- I'm turning over a new leaf in my Dexcool Discussions... attempting to shy away from a black & white view of Dexcool and assorted OAT coolants. Like many things in life, Dexcool can't be adequately described as 'good' or 'bad'... it just may be particulary suited (or unsuited) to certain applications & conditions- and the marketing, reputation, etc. may or may not be hype. Trying to separate the wheat from the chaff here, rather than painting with a broad brush.

So to that end, keep in mind that I'm NOT claiming here that Dexcool is the devil in liquid form. That said, I'd be remiss if I didn't correct the implications of your post. Cummins Engine Company has confirmed that the 2eha component of Texaco ELC did in fact cause gasket failures in Cummins engines- particularly with silicon seals. This is consistent with the failures that many of us have seen in GM intake gaskets, which used a silicon sealing bead... an issue that has been beat TO DEATH around here in discussions about GM's dexcool class action lawsuit.

So dexcool-haters have more than adequate reasons for their opinions- and are hardly throwing your list of companies 'under the bus'. GM lost a class-action suit on the matter. Cummins has explicitly stated that Texaco's coolant (using the same OAT as dexcool) directly caused problems with their engines... and you think that the second-hand, over-the-phone opinion of ONE Zerex engineer negates all this? When all he did was make an argument to follow their chart?

Sorry, I'm not convinced. And if 'engineer' is all that's required for credibility around here, then I reckon my own word will be law after about 2 more semesters' worth of classes.

Also, to repeat a (fairly obvious) point that I made earlier in this thread, Dexcool is not the same as assorted extended life coolants central to this discussion. There are important similarities- including the same manufacturs and the same corrosion inhibitors in some cases. But red, long-life (or extended-life) OAT coolant does not necessarily equal dexcool. It's an important distinction.

If there are any typos here... then ya'll can just deal with it. It's Christmas around here, and I'm using the inlaws' computer... with no spell-check add-on.
 
The OATS that I'm familiar with in Dexcool and similar coolants are carboxylate, sebacate, and 2eha. Dexcool is commonly said to use 2eha and/or sebacate- depending on manufacturer. I've also read that some import coolants (Honda in particular- probably others) use sebacate, but not 2eha. All heavy-duty ELC NOAT coolants (including Texaco ELC) that I'm aware of list carboxylate as their OAT inhibitor.

Conventional wisdom around here is that 2eha is primarily responsible for Dexcool's much-discussed gasket incompatibilities. Whereas other (import) OAT coolants primarily relying on sebacate have no such reputation. If one could determine with certainty that a particular manufacturer of Dexcool used only sebacate- then IMO, this would be preferable for obvious reasons.

An issue that came up earlier in this thread is whether Texaco ELC uses 2eha or carboxylate. The links from Cummins Engine Company indicate that Texaco ELC uses 2eha- leading to gasket problems. Whereas Texaco's own literature claims that their product uses carboxylate (as do all similar ELC's). This leaves only two possible scenarios as far as I can tell:

1. Texaco ELC initially used 2eha, then switched to carboxylate once the gasket incompatibilities became apparent

or

2. Carboxylate is a more general term that encompasses several compounds, including 2eha.

My chemistry education is limited on one semester of college-level chemistry, taken several years ago... along with a year of chemistry in high school (well over a decade ago). So if someone with a better background in organic chemistry could confirm or correct my conclusions, it would be appreciated. But I've found several links indicating that the latter option (2.) is the case:

http://www.scribd.com/doc/1621299/Environmental-Protection-Agency-c14172rt9

http://www.wipo.int/pctdb/en/wo.jsp?wo=1998039283&IA=WO1998039283&DISPLAY=DESC

http://answers.google.com/answers/threadview/id/591732.html

http://en.wikipedia.org/wiki/Hexanoic_acid

http://en.wikipedia.org/wiki/Carboxylic_acid

All of the prededing links (none of which are directly coolant-related) either explicitly state or imply that 2eha and similar compounds are carboxylates. Also, according to this link (http://en.wikipedia.org/wiki/Sebacic_acid), sebacic acid (the 'other' OAT used in dexcool) is also known as 1,8-octanedicarboxylic acid.

From all this, I will conclude that any coolant that lists "carboxylate" as the corrosion inhibitor may be using 2eha, sebacate, or any of several other related organic acids. In other words, carboxylate=OAT... and is no more specific than that.
 
I'll add to my previous post by noting that sodium benzoate, an inhibitor used in G05 antifreeze and Peak Global Lifetime coolant is also a carboxylate:

http://en.wikipedia.org/wiki/Carboxylic_acid

See aromatic carboxalic acids towards the bottom of the page.

So coolants that list "carboxylate" as their inhibitor are really telling you nothing except that this is an OAT coolant.
 
I agree here what is the point of using dex-cool if you are not going to use it for a 5 year change time. I mean other than satisfying a GM warranty there is no other reason to use it. ESPECIALLY if you have one of those problematic GM 6 cylinder engines. Personally I will never use dex-cool in any GM 4.3 or 6cyl engine that has a known dex-cool problem (or gasket problem to be more specific.) However, in other GM cars ( there is absolutely no reason to use dex in a car that does not specify it, no reason at all!) a GM car that has no known issues with dex like a 5.3 v8 I will have no second thoughts about using the product. I will change it out every 2 years with a new pressure resoivor cap or rad cap. But once out of warranty it is generally a good idea to use a regular green coolant that has no sludging or LIM gaskets killing abilities such as dex at 2 year change intervals.
 
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Originally Posted By: Gary Allan
Originally Posted By: PT1
if you don't change out coolant as part of a PM program...you will have problems with ANY coolant.


So is your cooling system PM set @ 5y/150kmiles? That's allegedly the longevity of Dexcool.

Which, if you're not going to take advantage of ..what's the point in using it?


Mine is 100k or 5 years for any coolant. On my boats I exchange 1-2 quarts each year with the premixed Dexcool because draining the closed cooling on those engines is a major PIA and I also use the prestone anti corrosion additive every year as well. This year I will change out the radiator caps & thermostats as part of the PM. So each engine will get about a 50% refill of new coolant. My Toyotas will get the Toyota factory coolant (pink). I usually do a drain fill on the radiator at 70k, 100k and 120k.
 
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Originally Posted By: PT1
Originally Posted By: Gary Allan
Originally Posted By: PT1
if you don't change out coolant as part of a PM program...you will have problems with ANY coolant.


So is your cooling system PM set @ 5y/150kmiles? That's allegedly the longevity of Dexcool.

Which, if you're not going to take advantage of ..what's the point in using it?


Mine is 100k or 5 years for any coolant. On my boats I exchange 1-2 quarts each year with the premixed Dexcool because draining the closed cooling on those engines is a major PIA and I also use the prestone anti corrosion additive every year as well. This year I will change out the radiator caps & thermostats as part of the PM. So each engine will get about a 50% refill of new coolant. My Toyotas will get the Toyota factory coolant (pink). I usually do a drain fill on the radiator at 70k, 100k and 120k.


Dexcool doesn't have a problem of going 5 years/150k miles. Texaco clearly stated it had iirc ~90+ of its corrosion inhibit properties after 5/150K miles. Plus it is rated to go more miles in HD applications that use a similar formula. Its problems with oxidation and possible gasket deterioration are independent of miles and change interval.
 
This is from a data sheet on Havoline, its a few years old...The life of a coolant in an automobile engine is limited by the corrosion protection ability of the
corrosion inhibitors. The main corrosion inhibitors in Havoline DEX-COOL® Extended Life
Anti-Freeze/Coolant has been shown to remain above 95% of their original concentration after
150,000 miles in automobiles. This allows much longer intervals between coolant changes without
worrying about loss of corrosion protection. Used Havoline Extended Life Anti-Freeze/Coolant
DEX-COOL® was tested in laboratory controlled corrosion tests for new coolants after it had
already been in service for more than 200,000 miles. The used Havoline Extended Life Anti-
Freeze/ Coolant DEX-COOL® passed the ASTM D 1384 requirements for glassware corrosion
with results equivalent to new coolants and also passed the ASTM D 4340 Aluminum Hot Surface
Test for new coolant. Havoline Extended Life Anti-Freeze/Coolant DEX-COOL® represents
the next generation of universal engine coolants. This coolant is suitable for a five year or 150,000
mile service life in automotive applications.
 
Yep, I have no doubts about Dexcools ability to last long and prevent corrosion in ideal situations like no air in system. I still wonder about it being aggressive with some plastic materials though. You got to hope and figure by now no one would spec an incompatible gasket for a Dexcool application though.
 
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