Originally Posted By: stalag
Originally Posted By: mechanicx
Why are you so critical of Dexcool and praise Cat ELC-1 which for all intents and purposes is 2-EHA containing Dexcool?
You being a chemist you should no better than that. Dexcool like any coolant was extensively tested on metals contained in cooling systems and performed very effectively for a very long service life. This is why it the most common HD coolant also.
A lot of people have pointed out that Dexcool requires the system to be full and free from air, best accomplished by using a pressurized reservior or degas bottle. The problems Dexcool had were not a chemistry problem per se, but mostly a poor gasket problem allowing the system to run low. That's the general nature of long life OAT coolants vs IAT, as OATs work best when the system is full.
Dexcool does not cause problems in all vehicles it was filled with even from the beginning back in 1995. And it doesn't cause problems on later models factory filled with it. All coolants have some shortcomings. For instance, the borates and nitrites in G-05 can attack aluminum when the other inhibitors become depleted, silicates may reduce water pump seal life etc. You know, Ford is going to Dexcool now and formulas similar to Dexcool are used in Europe. I think it's bad advice to say everyone should dump their Dexcool.
I have a distinct problem with the formulation of the base dexcool itself. Some of the problems of straight Dexcool are fixed with the nitrated/nitrited formulations. In 2008 when I first researched this issue, too many current posts were coming up with the sludging issue for their vehicles that contained dexcool. This was verified when I talked to Ford mechanics about this. It seems that Ford attempted to use straight Dexcool in one of their model lines. So many coolant related issues came up they dropped it and went to the G-05 coolants.
I have seen better results with the nitrated/nitrited versions of organic acid technology coolants. This is verified by the few to no issues with either the G-05 or the ELC-1 coolant. Also Caterpillar posts full information directly on their own formulation and on the testing required for certification as ELC-1 (this you must dig for since it is not easy to find). If either Prestone or Peak did this I would have far more comfort in recommendations of their formulations including any reformulated coolants they have. To date no coolant manufacturer/formulator has ever posted full technical data except for Caterpillar. However I made the exception for Zerex products because their coolant line is clearly labeled and if you buy the right coolant you will match easily what is already in your radiator from the automobile manufacturer.
That said no pressurized system is hermetically sealed and at STP a coolant system when cold does see air in the cooling system voids.
There is no way to get around this unless you fully seal the system. Pull a hard vacuum on the system (this would be less than 10 torr with 760 torr being defined as 1 atmosphere). Refill the system with Nitrogen and/or Argon. And this must be repeated no less than 3 times.
No coolant left beyond the life of the anticorrosive chemicals in solution will protect the engine. This fact is irrespective of who makes the coolant. Also it is a fact that almost all mechanics and DIY'ers will not use distilled water when distilled water is recommended by both the coolant manufacturers and the automobile manufacturers. The old silicate/phosphate formulation was tolerant of tap water but with Dexcool, ELC-1, G-05, or any other specialty coolant out in use today are all without exception not tap water tolerant.
The major reason silicate/phosphate coolant is not being recommended anymore was enunciated by the Caterpillar representative I spoke with. "The new coolant (ELC-1) has longer lasting protection and is not abrasive like the older coolant (silicate/phosphate base coolants). As a result as long as our coolant change procedures are followed to the letter, we have never seen a coolant related failure ever in relation to a cooling system converted to the new ELC-1 coolant." This statement was made in 2008 following the release of the coolant in 1995 thirteen years before.
I'll post this on this forum as well since you seem to be discussing in both places(Crown Vic Forum):
How do you know Cat ELC is not a Dexcool variant but a G-O5 variant? It would appear based on the following information that Cat ELC, made Texaco is/was originally called Dexcool Hd - Nitrited Dexcool.
http://www.penray.com/images/01.010.pdf
Based on the following links from Penray it would appear there are only four inhibitor packages used here in the US
Inhibitor package 2798-Dexcool:
http://www.penray.com/images/2798_InhibitorSheet_3.pdf
Inhibitor package 2798N - nitrited Dexcool package that is CatELC and compatible with Cat ELC:
http://www.penray.com/images/01.010.pdf
Penray Flyer stating that 2798N is Cat ELC:
http://www.penray.com/images/98.002.pdf
Penray 2705 Inhibitor package - Hybrid Ford/Chrysler:
http://www.penray.com/images/INH2705Flyer.1206.pdf
Penray 2792 Inhibitor Package - Fully formulated Convetional:
http://www.penray.com/managex/index.asp?x=313&y=314&articlesource=314&navID=
All Inhibitors:
http://www.penray.com/managex/index.asp?x=313&y=313&articlesource=313&navID=
I don't think its a big deal if its(Cat ELC) Dexcool or not based on your statement that if it is nitrited it will mitigate any compatibility issues. I certainly defer to chemical expertise.
Edit: Cat MSDS list Texaco as Manufacuter -
https://www2.itap.purdue.edu/msds/docs/12003.pdf