What type Coolant?

[Joseph S.]

I have read many threads referring coolant types that are best for our cars providing long term corrosion protection for cast iron, aluminum, and copper, solids buildup resistance, and heat rejection capacity in extreme conditions. The attached article from the Rockauto newsletter gives a pretty good overview of the various coolant types currently available.
It doesn't seem to change the consensus I have gotten from previous threads that G-05 coolants may be best for our cars.

Coolant/Antifreeze for Your Specific Vehicle

Engines built during the previous century almost universally used inorganic acid technology (IAT) coolant/antifreeze. Most newer vehicles use either longer lasting organic-acid inhibitor (OAT) coolant or hybrid organic acid technology (HOAT) coolant that offers both the corrosion resistance of IAT and the long life of OAT. To reduce gunk formation and maximize coolant life, it is best to not mix IAT, OAT and/or HOAT coolants together.IAT, OAT and HOAT coolants are all usually ethylene glycol-based, but they contain different additives. Coolant manufacturers' bottle labeling can be confusing if it includes a "Does NOT contain..." statement that could make it appear a traditional IAT coolant additive is inherently bad rather than just not the right additive (or quantity of additive) for that particular OAT or HOAT coolant. Reading "Does NOT contain..." could actually mean you should find a different coolant that "Does contain..." for your particular engine. Coolant that does not contain... Here are the benefits and/or drawbacks for some of the most common coolant additives mentioned on the coolant/antifreeze bottle labels:Amine: Amine was used to help prevent ferrous (iron) corrosion. In the '70s, it was found to react with nitrite, forming a carcinogenic substance, nitrosamine. Amine is no longer used in automotive coolant and "Does NOT contain Amine" is true even when unsaid.Borate: Borates have long been used to reduce acidity (pH) in IAT coolants. It is not compatible with some OAT and HOAT coolants that must maintain a different pH. Nitrite: Nitrite is used in coolant for heavy duty diesel and other engines to help prevent corrosion and pitting caused by cavitation (foaming bubbles). Nitrites oxidize aluminum and are generally not compatible with aluminum engines and cooling systems. Some coolants include both nitrites and additional additives that protect aluminum from oxidation.Phosphate: Phosphate is used to prevent corrosion in many IAT coolants. It coats metal preventing corrosion, but that coating can eventually flake off or form layers of scale, clogging the cooling system passages. Therefore, IAT coolants must typically be changed more frequently. Scale formation is a bigger problem if hard-water rather than distilled water is mixed with the coolant. Europe has lots of hard-water (and apparently little distilled water) so phosphate containing coolants are not used in most European brand vehicles. On the other hand, Asian vehicle manufacturers actually prefer coolant with phosphates and HOAT coolants designed for Asian brand vehicles usually include some phosphate. Silicate: Silicate is used in IAT coolants for corrosion protection, especially for aluminum. Asian vehicle manufacturers decided silicates are bad for water pump seals and reduce heat transfer. Therefore, coolants for most newer Asian brand vehicles do not contain silicates. On the other hand, European vehicle manufacturers think silicates are great for protecting aluminum from corrosion and HOAT coolants for European brand vehicles usually include silicates. So, in summary, HOAT coolants may contain nitrate, phosphate and/or silicate depending on what engines the coolant was designed for (Asian brand engines get phosphate, European brand engines get silicate). OAT coolants, such as Dex-Cool for GM vehicles, and coolants claiming they work in "all makes, all models, all colors" might not use any of the above additives, but instead rely on acid salt molecule coating and/or proprietary additives to prevent corrosion. Simply look under "Cooling System" in the RockAuto.com catalog to find the correct Coolant/Antifreeze for your specific vehicle or look under the "Tools & Universal Parts" tab and "Cooling System" to see all the Coolant/Antifreeze. Tom Taylor, RockAuto.com

[James W.]

Re: What type Coolant?

Zerex GO5 with distilled water, been using it for years in both of my C2 Corvettes. Be sure to flush and change it every five (5) years.

James

[Keith B.]

Re: What type Coolant?

got a question on using distilled water. had a online conversation and this was brought up about it:

During the distillation process, water is vaporized into its gaseous phase, so all its impurities are left behind. These impurities include a number of minerals, including “calcium” and “magnesium,” the two components of water “hardness.” The water is then condensed back into its liquid phase, so the resulting liquid is pure water – in fact, some of the purest water on earth. But the problem is that when water is distilled, or “stripped,” of its minerals and impurities, the resulting solution is composed of chemically imbalanced “ions.” This leaves distilled water “ionically hungry,” so it will actually strip electrons from the metals in a cooling system as it attempts to chemically re-balance itself. As it chemically removes electrons from the metals of cooling system components, distilled water eventually does extreme damage that could lead to cooling system failure.

so is there any truth to this statement or cause of concern

[Duke W.]

Re: What type Coolant?

There's a myth going back decades that you should run "pure water" (not blended with antifreeze) in your cooling system because tap water has too many minerals, which are bad

Pure distilled or deionized water will leach ions from metal, however, once you mix the distilled water with anti-freeze it's no longer pure water because it now contains "good ions" and chemicals contained in the antifreeze that prevent corrosion of cooling system materials. Although most OEMs say potable tap water is okay to use, most contain various ions that may be undesirable, so distilled is the best to mix with an antifreeze that has a corrosion protection package designed to protect all metals in a car's cooling system.


Modern OAT types may not be the best for solder, which modern cars don't have, so HOATs are the best for vintage cars that have copper radiators and heater cores. IAT is basically obsolete.. Those who got sucked into this bad advice paid a price, especially if there were any aluminum components in the cooling system.50/50 blend of Zerex G-05 and distilled water is the way to go.

Duke

[Joe L.]

Re: What type Coolant?

Pure distilled or deionized water will leach ions from metal, however, once you mix the distilled water with anti-freeze it's no longer pure water because it now contains "good ions" and chemicals contained in the antifreeze that prevent corrosion of cooling system materials.


Duke

Duke and Keith-----

Absolutely correct. Distilled water would be very bad for a cooling system if it were used by itself.That should never be done.

I'll also add that if one lives in an area with tap water that is low in total dissolved solids (TDS), that can be used safely in place of distilled water for the coolant/water mix. Check the annual water analysis that your water system operator is supposed to provide you with.

[Keith B.]

Re: What type Coolant?

Joe and Duke thanks for the info. I have using distilled water and coolant 50/50 mix for years. I like using distilled water jugs as it’s easier to measure how much your mixing and where I grew up was on well water and I know it was heavy in minerals. As it left hard water spots on EVERY thing. Sometimes with online conversations it takes a little to grasp what’s true and false. And need info from people you can trust. And so fair everything Duke and you Joe have written you can take to the bank on truth and helpfulness.

[Frank D.]

Re: What type Coolant?

You guys are making me paranoid -- I may do a flush and fill on the split window since I'm "locked down" anyway...

A question, one of my block drain plugs is badly munged and not coming out; is the one "working" plug on the DS of my 250hp motor enough to get a good flush and any crud out ?? The engine is diligently maintained so I'm thinking there can't be much "junk" (rust, etc.) in the block anyway -- never seen any come out.

[George C.]

Re: What type Coolant?

I don't know what the general consensus will be. I just drained mine a couple of days ago and was surprised at how much was in the second side of the block. No way to be sure yet, but think I got about a gallon out of each side.
I suggest removing the lower ignition shielding before trying to drain the block. You can guess why I am suggesting that.

I am also a little paranoid about Antifreeze type I just flushed and refilled with Distilled water and a CarQuest "all brands/all types" Green antifreeze. I can't find a type, OAT, HOAT on the label.
George

You guys are making me paranoid -- I may do a flush and fill on the split window since I'm "locked down" anyway...

A question, one of my block drain plugs is badly munged and not coming out; is the one "working" plug on the DS of my 250hp motor enough to get a good flush and any crud out ?? The engine is diligently maintained so I'm thinking there can't be much "junk" (rust, etc.) in the block anyway -- never seen any come out.

[Joe L.]

Re: What type Coolant?

You guys are making me paranoid -- I may do a flush and fill on the split window since I'm "locked down" anyway...

A question, one of my block drain plugs is badly munged and not coming out; is the one "working" plug on the DS of my 250hp motor enough to get a good flush and any crud out ?? The engine is diligently maintained so I'm thinking there can't be much "junk" (rust, etc.) in the block anyway -- never seen any come out.

Frank------


Well, getting one out is better than getting none out but it's not as good as getting both out. But, I expect you know that anyway. I would not attempt at getting the one that's stuck out, though. Often times, these things are frozen so tightly that it's virtually impossible to get them out. I've even heard of cases of folks cracking the block trying to do it although I've never verified those stories.

Want to get a really good coolant flush? Use a Prestone "Flush and Fill" kit. If you live in an area with low TDS water, this is a near perfect solution. If you have high TDS water, you will be left with at least some of this in your system but I don't think it's really too much of a problem. After the flush and drain of the radiator, add enough concentrated coolant to achieve the percent coolant you want (I always use 60%) and then add enough distilled water to fill the system.

[Joe L.]

Re: What type Coolant?

I don't know what the general consensus will be. I just drained mine a couple of days ago and was surprised at how much was in the second side of the block. No way to be sure yet, but think I got about a gallon out of each side.
I suggest removing the lower ignition shielding before trying to drain the block. You can guess why I am suggesting that.

I am also a little paranoid about Antifreeze type I just flushed and refilled with Distilled water and a CarQuest "all brands/all types" Green antifreeze. I can't find a type, OAT, HOAT on the label.
George

George-----


You won't find those designations on the label. However, if you use Zerex G-05 you will have a HOAT coolant. Zerex G-05 is the only commonly available HOAT coolant I know of. The "all brands/all types" coolant is not a HOAT coolant. It's a "one size fits all" type of thing. You should know how that usually goes.

[Frank D.]

Re: What type Coolant?

Frank------


Well, getting one out is better than getting none out but it's not as good as getting both out. But, I expect you know that anyway. I would not attempt at getting the one that's stuck out, though. Often times, these things are frozen so tightly that it's virtually impossible to get them out. I've even heard of cases of folks cracking the block trying to do it although I've never verified those stories.

Want to get a really good coolant flush? Use a Prestone "Flush and Fill" kit. If you live in an area with low TDS water, this is a near perfect solution. If you have high TDS water, you will be left with at least some of this in your system but I don't think it's really too much of a problem. After the flush and drain of the radiator, add enough concentrated coolant to achieve the percent coolant you want (I always use 60%) and then add enough distilled water to fill the system.

Thanks - yes, a guy on the Corvette Forum drilled into a cylinder wall (he says) trying to remove a block drain....not gonna try it..

[George C.]

Re: What type Coolant?

George-----


You won't find those designations on the label. However, if you use Zerex G-05 you will have a HOAT coolant. Zerex G-05 is the only commonly available HOAT coolant I know of. The "all brands/all types" coolant is not a HOAT coolant. It's a "one size fits all" type of thing. You should know how that usually goes.

Joe,
Oh yes, one size fits all usually means it doesn't do any job we.
I will switch it. to the Zerex G-05, and it won't be long before I do it. I now have a leaking block drain plug. I noticed one side the pug had nasty threads, so I went and bought a new plug. Even the new one doesn't tighten up well, and I have a damn leak.
I need to go research the fix. I am guessing it needs tapped out to a r/3" NPT and replace the plug.
George

[Joe L.]

Re: What type Coolant?

Joe,
Oh yes, one size fits all usually means it doesn't do any job we.
I will switch it. to the Zerex G-05, and it won't be long before I do it. I now have a leaking block drain plug. I noticed one side the pug had nasty threads, so I went and bought a new plug. Even the new one doesn't tighten up well, and I have a damn leak.
I need to go research the fix. I am guessing it needs tapped out to a r/3" NPT and replace the plug.
George

George------


If the threads in the block are damaged, there are Heli-Coil kits available to install inserts.

[George C.]

Re: What type Coolant?

George------


If the threads in the block are damaged, there are Heli-Coil kits available to install inserts.

Joe,
I am afraid the threads in the block are damaged. Both the old and new plug threaded all the way in flush. I use ARP Thread sealant and it stopped dripping after a couple hours. I just don't want to trust it long term.
I didn't think about a Heli-coil because of the water jacket. But I can pick up a kit at our local Fastener store
Thanks for the idea.
George

[Joe L.]

Re: What type Coolant?

Joe,
I am afraid the threads in the block are damaged. Both the old and new plug threaded all the way in flush. I use ARP Thread sealant and it stopped dripping after a couple hours. I just don't want to trust it long term.
I didn't think about a Heli-coil because of the water jacket. But I can pick up a kit at our local Fastener store
Thanks for the idea.
George

George-----

Yes, I would go with a Heli-Coil before just drilling and tapping it for the next larger pipe plug. That's because this tapping in the block is into a boss. The boss provides the extra material and thickness for the tapping. A larger NPT tapping might, essentially, eliminate the boss.