Topic: So, changing coolant and don't want Dex-Cool? Read on, you may be surprised...

[TomatoSoup]

I started to do some research on-line about pros/cons of Dex-cool based on DDM's coolant change procedure thread (here: http://www.kappaperformance.com/forum/index.php/topic,7629.25.html) where Dave said they tend to not use Dex-cool when they can, but use local auto-parts coolant instead.

For the pro/con Dex-cool argument, I found that no-one really knows... it's just religion.  "Dex-cool ruins your engine" - "No it doesn't"; makes up pretty much all the arguments. Aggh.

BUT then I started seeing posts about how the majority (if not all) of the aftermarket AMAM (All Makes All Models) antifreezes are actually Dex-cool equivalent formulations, including the Advanced Auto stuff Dave said they use.  It seems that Dex-cool boils down to (see what I did there?) really just the combination of Ethylene Glycol and corrosion inhibitors in the form of organic acid technology (OAT), generally either Potassium or Sodium 2-Ethyl Hexanoic Acid (2EHA).

Being from Missouri (not really) I started looking up MSDS sheets to see what actually was in the different formulations, and I found exactly what I saw claimed above.  For example, for Advanced Auto's 50/50 AMAM antifreeze (actually made by Prestone), the MSDS shows:

   Ethylene Glycol (107-21-1) 40-60%
   Diethylene Glycol (111-46-6) 0-5%
   2-Ethyl Hexanoic Acid, Sodium Salt (19766-89-3) 1-5%
   [Water 40-60%]

Thus, at least in general, possibly for all, the store-bought versions of AMAM antifreezes around, are all basically Dex-cool formulations. Almost no getting away from it!

Now there ARE non-dex formulations out there, but you actively have to look for them (and they are NOT classified as AMAM).  An example is Peak's "Peak Global" Antifreeze (note: NOT the 'all makes' or 'Dex-cool' type).  But those may well not be compatible with our cars anyway.

-------
References:
If you want to look up this MSDS info yourself, these are some of the MSDS links I found:

Advanced Auto: http://www.aapmsds.com/default.aspx - search for "AF7502" and "Product Number"
Halvoline Dex-cool: https://cglapps.chevron.com/msdspds/MSDSDetailPage.aspx?docDataId=34272&docFormat=PDF
ACDelco Dex-cool (GM Canada - actually Prestone brand): http://www.centralstatesbus.com/MSDS/ACDelco%20Anti%20Freeze.pdf
NAPA Dex-cool: https://partimages.genpt.com/partimages/946011.pdf
Zerex Dex-cool: https://partimages.genpt.com/partimages/728574.pdf

and a bunch more here: http://hazard.com/msds/gn.cgi?query=ANTIFREEZE

Finally, the posts that triggered all this for me: http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2471312 and http://forums.corral.net/forums/general-mustang-tech/1380322-all-makes-all-models-green-coolant-dexcool-beware.html

[Dave@DDMworks]

I started to do some research on-line about pros/cons of Dex-cool based on DDM's coolant change procedure thread (here: http://www.kappaperformance.com/forum/index.php/topic,7629.25.html) where Dave said they tend to not use Dex-cool when they can, but use local auto-parts coolant instead.

For the pro/con Dex-cool argument, I found that no-one really knows... it's just religion.  "Dex-cool ruins your engine" - "No it doesn't"; makes up pretty much all the arguments. Aggh.

BUT then I started seeing posts about how the majority (if not all) of the aftermarket AMAM (All Makes All Models) antifreezes are actually Dex-cool equivalent formulations, including the Advanced Auto stuff Dave said they use.  It seems that Dex-cool boils down to (see what I did there?) really just the combination of Ethylene Glycol and corrosion inhibitors in the form of organic acid technology (OAT), generally either Potassium or Sodium 2-Ethyl Hexanoic Acid (2EHA).

Being from Missouri (not really) I started looking up MSDS sheets to see what actually was in the different formulations, and I found exactly what I saw claimed above.  For example, for Advanced Auto's 50/50 AMAM antifreeze (actually made by Prestone), the MSDS shows:

   Ethylene Glycol (107-21-1) 40-60%
   Diethylene Glycol (111-46-6) 0-5%
   2-Ethyl Hexanoic Acid, Sodium Salt (19766-89-3) 1-5%
   [Water 40-60%]

Thus, at least in general, possibly for all, the store-bought versions of AMAM antifreezes around, are all basically Dex-cool formulations. Almost no getting away from it!

Now there ARE non-dex formulations out there, but you actively have to look for them (and they are NOT classified as AMAM).  An example is Peak's "Peak Global" Antifreeze (note: NOT the 'all makes' or 'Dex-cool' type).  But those may well not be compatible with our cars anyway.

-------
References:
If you want to look up this MSDS info yourself, these are some of the MSDS links I found:

Advanced Auto: http://www.aapmsds.com/default.aspx - search for "AF7502" and "Product Number"
Halvoline Dex-cool: https://cglapps.chevron.com/msdspds/MSDSDetailPage.aspx?docDataId=34272&docFormat=PDF
ACDelco Dex-cool (GM Canada - actually Prestone brand): http://www.centralstatesbus.com/MSDS/ACDelco%20Anti%20Freeze.pdf
NAPA Dex-cool: https://partimages.genpt.com/partimages/946011.pdf
Zerex Dex-cool: https://partimages.genpt.com/partimages/728574.pdf

and a bunch more here: http://hazard.com/msds/gn.cgi?query=ANTIFREEZE

Finally, the posts that triggered all this for me: http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2471312 and http://forums.corral.net/forums/general-mustang-tech/1380322-all-makes-all-models-green-coolant-dexcool-beware.html

I love it when someone actually takes the time to look up real information, nice job. Honestly, we just always used it because it was a pain to have to have Dexcool for the GM cars, something else for the Miata's and the funky blue stuff for the MINI's. The advance stuff plays well with all of the others and is only one thing we have to have here.

Thanks again for actually doing the research on it.

[TomatoSoup]

I always thought of Dexcool as being a 5 year coolant from any manufacturer, as a generic term. Is there a spec we need to look for on the bottle so we know it's compatible or is it good enough that it's the amber colour?

Actually, color has nothing to do with it any more.  Those ones I mentioned come in yellow, green, orange, etc.  All the different makers seem to have a brand that's labeled "Dex-cool compatible" (though that's likely just 'badge engineering' ) so you can look for that.

I love it when someone actually takes the time to look up real information, nice job. Honestly, we just always used it because it was a pain to have to have Dexcool for the GM cars, something else for the Miata's and the funky blue stuff for the MINI's. The advance stuff plays well with all of the others and is only one thing we have to have here.

Thanks again for actually doing the research on it.

You are welcome

[Sly Bob]

The capacities are below from the manual but I would assume that a gallon is enough to do a complete fluid change as it's generally impossible to completely evacuate the system.

The manual says to "Always use DEX-COOL® (silicate-free) coolant in your vehicle". I wonder if the other fluids are silicate free as well.

__________________________________________________________________________

Capacities and Specifications
The following approximate capacities are given in English and metric conversions. Please refer to Recommended
Fluids and Lubricants on page 6-12 for more information.

Cooling System
2.0L Engine Automatic 9.2 qt, 8.7 L
2.0L Engine Manual 9.5 qt, 9.0 L
2.4L Engine Automatic 8.7 qt, 8.2 L
2.4L Engine Manual 8.9 qt, 8.4 L

All capacities are approximate. When adding, be sure to fill to the appropriate level, as recommended in this
manual.

[Dave@DDMworks]

The capacities are below from the manual but I would assume that a gallon is enough to do a complete fluid change as it's generally impossible to completely evacuate the system.

The manual says to "Always use DEX-COOL® (silicate-free) coolant in your vehicle". I wonder if the other fluids are silicate free as well.

__________________________________________________________________________

Capacities and Specifications
The following approximate capacities are given in English and metric conversions. Please refer to Recommended
Fluids and Lubricants on page 6-12 for more information.

Cooling System
2.0L Engine Automatic 9.2 qt, 8.7 L
2.0L Engine Manual 9.5 qt, 9.0 L
2.4L Engine Automatic 8.7 qt, 8.2 L
2.4L Engine Manual 8.9 qt, 8.4 L

All capacities are approximate. When adding, be sure to fill to the appropriate level, as recommended in this
manual.

I wonder if those capacities are with or without the oil cooler found on some 2.0L and 2.4L engines.

[TomatoSoup]

The manual says to "Always use DEX-COOL® (silicate-free) coolant in your vehicle". I wonder if the other fluids are silicate free as well.

Yes.  That's one of the big differences between the older and newer antifreezes.  The ones I noted are all silicate free and will say so on the label.

[Sly Bob]

Dave, do you find a gallon of the concentrate is usually enough to do a complete change?

[TomatoSoup]

Dave, do you find a gallon is usually enough to do a complete change?

I'd suggest getting two gallons of 50/50 and using some as a partial fill & drain to help flush the old.
(Or a gallon of concentrate and a gallon of distilled water and mix your own )

[Sly Bob]

Oh I ALWAYS use the concentrate. Why pay for water when I have a perfectly good tap on the side of the house?   

Doing a little research on my own and it looks like asking what the best coolant is, is kindo' like asking what the best oil or wax is. Everyone has a different opinion.

Gotta do a coolant change and check valve install when I get the car out of storage and as all my cars run Dex-cool anyway, I'll just get a jug of that at Autozone or somewhere.

[Dave@DDMworks]

Dave, do you find a gallon of the concentrate is usually enough to do a complete change?

We always buy concentrate and mix it here, since we have so many extra bottles of antifreeze it makes it easy.

[Sly Bob]

  So a gallon should do it?

[tallcraig]

I flush with distilled water and mix with the same.

[2kwk4u]

I believe a fair amount of the DexCool horror stories (maybe even a majority) stem from other problems.  For example, GM V6 engines of a certain generation were notorious for developing intake manifold gasket leaks. 

In my case, it was an L67 / "3800 Series II" supercharged Grand Prix GTP lower intake manifold gasket.  DexCool was blamed for causing the leaks, but in the case of the car I had, I'd blame neglect first.  It had 138,000 miles on it when I bought it used (a '98 model in 2006), and I doubt the coolant had ever been changed.  The "Dex-sludge" in the overflow tank and on the underside of the radiator cap should have tipped me off that I had a problem.  Instead, I ignored it b/c I bought the car as a beater. 

Eventually, temps started running high.  The worst case was when we drove it to Berlin from Ramstein (5 or so autobahn hours - I was stationed in Germany at the time).  It overheated and the radiator ran dry on me several times.  Instead of giving a damn, though, I'd just limp it along to the next exit or rest stop, let it cool off a bit, and fill that bad boy up with water...  figuring worst it would hard-break and we'd have it towed to a salvage yard and make our way to Berlin on a train from there on.  That never happened. 

When we got back home, I decided I finally had enough.  Wound up replacing the upper and lower intake manifold gaskets, water pump, radiator, and all hoses.  Surprisingly somehow the heater core was a champ the whole time.  The dex-sludge definitely took its toll, but the damn car never left me stranded, no matter how badly I neglected it.

Check out what the water pump looked like, though...



Incidentally, when I re-filled it after the repair, I was SURE to use Dex-cool. 

[Gentleman Jack]

TS-
You are my (second) hero. I love your attention to detail. If I thought I had half as much patience as I need, I'd come live with you to learn your ways. You might be my Yoda.

DDM-
I miss you.

SlyBob-
A gallon if concentrated awesome will fix anything.

2qwk-
That water pump looks fine. Can you donate that for the raffle at the mod meet?  Water pumps are a potential issue on the kappa and someone would love to have a spare.

[ChopTop]

Have an article I'm reading on waterless coolant, found a couple vids.

Jay Leno's Garage: Waterless Engine Coolant

Evans Waterless Engine Coolant Power Cool 180° in a Kettle Test!

[Treeman]

Great info - thanks!

[TomatoSoup]

TS-
You are my (second) hero. I love your attention to detail. If I thought I had half as much patience as I need, I'd come live with you to learn your ways. You might be my Yoda.

Awwww, shucks