Antifreeze Info ~ orange or green?

[Brian in Wheeling]

What do you use and why? I know some don't use it. But what are the consideration?
Brian W.

[tbirdtbird]

isn't the orange just propylene glycol.....calling Mitch.....he works the vintage and the moderns

EDIT: OK, the orange I was thinking was propylene glycol is NOT what this is, my bad. Keep reading to have Mitch set the record straight, Dave

[Mitch]

Stay away from the orange dexcool in an old car, it eats old style radiators with lead solder and does not protect very good to stop corrosion in the blocks. Open up a cooling system on any GM car using orange dexcool and its a total damn mess. Stick with the good old school green and your car will be much more happier

[tbirdtbird]

Hmmmmm so I need to get some green in my Silverado???

[Mitch]

Well that's your call
GM has been sued for gasket and corrosion issues from the dexcool product, but they continue to stand behind it. You have to be careful mixing the two as it can gel and block the heater core and or radiator. I don't buy the 6 year 150,000 mile change interval
Changing it out, hmmm i have done it many times for that reason
The corrosion protection sucks IMO

[Rowdy]

I am with Mitch all the way with using only the green anti-freeze. Wish the previous owner of my wifes car would have drained the dexcool, ,flushed the system and put the green stuff in early on. Have changed head gaskets once and intake gaskets another 2 times due to the corrosion issues caused by the junk. Keep in mind that they had to make the gaskets out of molded RTV as this stuff is agressive towards older style gaskets. Rod

[tbirdtbird]

what was the point of the dexcool

[DaWizard]

Beware of Prestone, it has a tendency to bubble and froth and that isn't good in a Model A.

[Dennis]

What about the Ford Gold coolant? Back in the early 2000s, they were recommending in fact insisting it's use for their diesel pickups. What's your take on that stuff? I had to chuckle to myself earlier this afternoon when I was skimming through my Model "A" Instruction Book. "Buy only genuine Ford products, all others are inferior". "A suitable anti-freeze solution can be obtained from any authorized Ford dealer. As anti-freeze solutions usually contain alcohol, care should be used when filling the radiator not to spill any of the solution, as it may damage the proxylin finish." :rolling Never mind how rusted your block and radiator are going to be, that's what the petcock at the lower connection is for. Just get the hose and flush until the water running out is clear.

[CountrySquire55]

I use a 50/50 mixture of Sierra antifreeze and distilled water since Sierra is supposed to be much less foamy in the non-pressurized Model a cooling system. Seems to work just fine for me.

[BNCHIEF]

That is what my engine builder suggested and it seems to work well for me as well.

[Mitch]

what was the point of the dexcool

From Wikipedia

Certain cars are built with organic acid technology (OAT) antifreeze (e.g., DEX-COOL^[24]), or with a hybrid organic acid technology (HOAT) formulation (e.g., Zerex G-05),^[25] both of which are claimed to have an extended service life of five years or 240,000 km (150,000 mi).

DEX-COOL specifically has caused controversy. Litigation has linked it with intake manifold gasket failures in General Motors' (GM's) 3.1L and 3.4L engines, and with other failures in 3.8L and 4.3L engines. One of the anti-corrosion components presented as sodium or Potassium 2-ethylhexanoate and ethylhexanoic acid is incompatible with nylon 6,6 and silicone rubber, and is a known plasticizer. Class action lawsuits were registered in several states, and in Canada,^[26] to address some of these claims. The first of these to reach a decision was in Missouri, where a settlement was announced early in December 2007.^[27] Late in March 2008, GM agreed to compensate complainants in the remaining 49 states.^[28] GM (Motors Liquidation Company) filed for bankruptcy in 2009, which tied up the outstanding claims until a court determines who gets paid.^[29]

According to the DEX-COOL manufacturer, "mixing a 'green' [non-OAT] coolant with DEX-COOL reduces the batch's change interval to 2 years or 30,000 miles, but will otherwise cause no damage to the engine".^[30]DEX-COOL antifreeze uses two inhibitors: sebacate and 2-EHA (2-ethylhexanoic acid), the latter which works well with the hard water found in the United States, but is a plasticizer that can cause gaskets to leak.^[22]

According to internal GM documents,^{[citation needed]} the ultimate culprit appears to be operating vehicles for long periods of time with low coolant levels. The low coolant is caused by pressure caps that fail in the open position. (The new caps and recovery bottles were introduced at the same time as DEX-COOL). This exposes hot engine components to air and vapors, causing corrosion and contamination of the coolant with iron oxide particles, which in turn can aggravate the pressure cap problem as contamination holds the caps open permanently.^[31]

Honda and Toyota's new extended life coolant use OAT with sebacate, but without the 2-EHA. Some added phosphates provide protection while the OAT builds up.^[22] Honda specifically excludes 2-EHA from their formulas.

Typically, OAT antifreeze contains an orange dye to differentiate it from the conventional glycol-based coolants (green or yellow). Some of the newer OAT coolants claim to be compatible with all types of OAT and glycol-based coolants; these are typically green or yellow in color (for a table of c


With real world experience this crap does not protect from corrosion long before the recommended service interval if it even does at all

[tbirdtbird]

Yikes!!! You already had me convinced, but now flushing that crap has a whole new priority
Leave it to GM

And the pressure cap is no longer on the rad tank, it is the plastic cap on the overflow bottle and I already had that crack and leak.
Some of those drafting table design guys need to have their french curves and dividers taken away...

[BNCHIEF]

I do not have that in anything I own but great info to know. Ford has done some dumb things in the past as well as they all have.

[plyfor]

Check out the following article which may make the discussion even more confusing !
We use diluted Sierra or others in teen thru 50's cars that come thru , careful to leave expansion space in the radiators.

[Dennis]

Propylene Glycol based coolant... I'll have to look at what I have in my cabinet.

[tbirdtbird]

Mitch, Miles who as you know also works on moderns as well as vintage at the dealership, totally agrees with you that the OAT stuff (orange dexcool) is total garbage, and they drain and flush it out there also.
I suggested that GM did it because it was cheaper, and he added that he thinks it is to increase work at the dealership since the problems don't seem to show up until the 3-yr drivetrain warranty is up. The existence of the lawsuits is compelling. He and I joked that the 2 of us had never gotten around to talking about this!
I will test the pH of the stuff before I flush it. If it is less than 8.0, then it will NOT inhibit corrosion

[Mitch]

Yea it's like a time bomb waiting to blow!! Good thoughts

[Dennis]

Had to go to the parts store tonight so I thought I'd look for the Propylene Glycol while I was there. All of the brands they had stocked, no sierra brand in the store that I could find, except for one were the regular Ethylene glycol. And down on the bottom shelf was the Winter-EEZ RV and Marine Antifreeze. Now on the label on the right side it reads "not intended for use in engines. Hmmm Maybe that's because it's less than half the price of the others. However on the left side of the label it reads use undiluted and as directed, Provides burst protection to -50 degrees. Is compatible with metal and plastic components. Provides excellent corrosion protection. Odorless. Non-toxic/non-staining. So what's your opinion on that?

[tbirdtbird]

Dennis, what is "Winter-EEZ RV and Marine Antifreeze" made from?

There may be confusion that OAT based antifreeze is the same as propylene glycol, and it isn't.
I may have contributed to that early in the thread, because I thought the orange was prop. glycol, and I had never heard of OAT based antifreeze until Mitch cleared that up.
I have edited my post to acknowledge my error

[Dennis]

Good question what it's made from, I couldn't find anything yet what it's made from. I found a few other brand names made for engine coolant that contain propylene glycol. Read post #19

[tbirdtbird]

OK, I just tested the pH of the Dexcool (OAT based antifreeze) in my '09 Silverado, 50K miles.
It is 6.5
This will never do.
At a shop I worked in 40 years ago we had a highly knowledgeable Prestone rep and he told us to maintain the pH of antifreeze at 8.0 to avoid corrosion. Thinking back thru high school chemistry, pH 8 is slightly alkaline, and alkaline does not harm engine blocks. Remember in the old days machine shops would hot tank blocks in lye (alkaline) solution, all the time.
A pH of 6.5 is clearly acidic, and is gonna corrode the metals in the engine, and eat away at gasket sealers, etc

It would seem the chief antifreeze engineer at GM flunked high school chemistry. I can't wait to flush that stuff out of my truck

Thanks, Mitch for setting me straight

[Mitch]

Dave it's all about sharing info and helping one another, your welcome

you helped me out many times also so Thank you

I thank Brian for starting this informative thread.

[Dennis]

In answer to tbirdtbird, earlier what propylene glycol is made from I wasn't able to find an answer to that. I did find a few made for engine use.

Good question what it's made from, I couldn't find anything yet what it's made from. I found a few other brand names made for engine coolant that contain propylene glycol. All of those advertise as biodegradable. For instance Peak has a formula they have labeled Sierra. Some call theirs synthetic such as Star Bright Premium Synthetic and when you read their label they mention it contains propylene glycol. All of the propylene glycol for engine use is expensive that I was able to find. Prestone even has a Low Tox that is propylene glycol. Prestone Low Tox was the lowest price at Amazon for $24.59 a gallon or for 6 gallon $97.97

[DaWizard]

Does it matter that I run tap water and soluble oil? That is only cost me a few bucks for a gallon of machinist water soluble oil and that because it mixes easily with water works well for cooling? And since it is less than $20.00 a gallon and I only use about a cup per 3 gallons of water, I can change it as often as I deem it gets dirty?

[Dennis]

I'd be concerned about the compatability with gaskets. When I was working for construction companies, we rented shoring that had hydraulic jacks that locked in place, they had soluable oil in them of some kind because of the leaks of regular hydraulic oil and contamination.

[Denis4x4]

In as much as older cars tend to leak from time to time, I'm an advocate of Sierra as it is pet friendly. It costs more and getting harder to find.

[Tom Wesenberg]

Boy, that good stuff you learn here!

I don't know what the RV toilet and drain pipe antifreeze is made from, but you can bet it doesn't have water pump lubricant in it.

[Dennis]

Tom, isn't there an additive we could use to alleviate that problem with water pump lubrication?

[dahrens1]

I had been considering using 50/50 blend of the Sierra antifreeze (PG) which I believe is made by Peak which is part of Old World Industries, Inc. located in Northbrook, IL because I liked it's low toxicity for pets, wild animals, and the environment in general in case of a leak or accidental spill. From the article posted earlier it seems like a good choice for our older cars. Performance wise it is equal to or exceeds that of ethylene glycol in most cases. More info can be found at https://peakauto.com/products/antifr...motive/sierra/

Dave

[Tom Wesenberg]

Tom, isn't there an additive we could use to alleviate that problem with water pump lubrication?

Yes, but I still wouldn't use the drain pipe antifreeze.

[Dennis]

Looking for the automotive type propylene glycol locally. And of course I decide to click on the link Dave posted in #23 and see several locals in my area are supposed to have it. I'll have to look at those places...

[Mitch]

Do not use RV antifreeze in your engine to run it

[Dennis]

Looking for the automotive type propylene glycol locally. Supposed to be available several places around me. Thanks to Dave for posting that link in #24