Issue Many Are Ignoring: Most Coolants Contain 2-EHA (which 'eats' silicone)
 

This may or may not be news to you personally, but it will undoubtedly be news to some, and it warrants attention.

Most of the all makes/all models coolants/antifreezes sold at places like Advanced Auto, Autozone, Walmart, Pepboys, O'Reilly's, and other stores contain 2-ethylhexanoate (2-EHA).

Essentially, these coolants are Dexcool clones (without explicitly stating such, so as to avoid having to pay GM royalty fees).

Why is this important? Well, without getting into a debate with those who believe Dexcool & other 2-EHA containing coolants are or are not fine, let's look at what the Society of Automotive Engineers has to say about 2-EHA (in a recent article speaking to industry-wide changes in OEM coolants being used):

Chrysler switches to OAT antifreeze

Chrysler switches to OAT antifreeze for longer service interval
Okay, if one has enough concern about the potential that the SAE is correct (as well as other groups and companies, such as Gates), it's probably prudent to understand whether the RX-8 uses any silicone in sealing gaskets, hoses or other components in its cooling system, correct?

On this point, I will defer to the experts for an absolute answer, but I do believe that at LEAST the 8's coolant hose is silicone, and possibly gaskets, as well.

If this IS the case, shouldn't this be a matter of serious concern, given that coolant leaking into the Renesis is likely to lead to catastrophic failure?

Mazda's FL22 and Motorcraft Specialty Green Engine Coolant (PN# VC-10-A premixed or VC-10-A2 normal concentration) are essentially the same exact coolant, neither of them contain any 2-EHA, this is what Mazda has been using for a while now, while Ford has conspicuously switched to this in its new vehicles as a factory fill coolant (in other words, Ford took a page out of Mazda's factory fill requirements).

Doesn't this speak loudly to the fact that there's an issue with coolant that contains 2-EHA?

Given that coolant is one of the most mission critical fluids in properly maintaining one's motor, and that it's also probably one of the most neglected fluids by vehicle owners, I would have expected to see a lot more discussion of this issue here on RXclub, but there's not much I was able to find.

Whether you agree or disagree with what I've had to say, and hopefully after you've done your own due diligence in the event you weren't already up to speed on this issue, I think this is an important matter that warrants more discussion.

Here's a gasket from a system using 2-EHA containing coolant and one from a system that DOES NOT, side by side (same motor - 3800 Series II Buick):

http://www.dex-cool.net/victims.JPG
On the left is the DEX 30,000-40,000 mile LIM gaskets........On the right, the 125,000 mile non-DEX gaskets


http://www.dex-cool.net/lim_gaskets.jpg

These pics and more are in my Article 1 link below.

Roto

Bonus Article on Coolant Technology that is Extremely Good
 

Edit - Here are the articles I meant to post, and they are fantastic.

The first one is less "professional," and not from an industry source, but has fantastic photos of gaskets from the same GM 3800 series V6 motors where some used Dexcool and some did not, and the differences are incredible.

The second article is more professional, but easy to read, and does an amazing job summarizing the hazards of using any coolant with 2-EHA in it (which is probably in 85% of the coolants sold at the typical auto parts store or Walmart).

Article 1:

http://www.dex-cool.net/

Article 2:

http://www.mastertechmag.com/pdf/200...antifreeze.pdf

Good stuff man, good to know. My last reman died prematurely of a faulty coolant seal. There was a shit ton of silicone used in that engine and possibly RTV silicone used to hold the coolant seals in place instead of Vaseline.

So would using distilled water and water wetter be a safer option?

Probably not because it doesn't stop scale and contaminants from building up. Not sure what is in water wetter.

Or just use Mazda's FL22 coolant.

I think I might just go do that. Scary stuff! 0.0

I usually use FL-22 but I was lazy the last time I redid the coolant lines to my turbo and topped off with Autozone brand coolant. It's probably a non issue with such a small amount but I guess I'll do a flush and put in fresh FL22 just to keep my OCD from kicking in.

Only a very few people, living in very warm places year round, could get away with using distilled water and something like water wetter.

Even then, they risk an issue if they get a cold weather event type anomaly.

Remember, water does the cooling and heat transfer, and the ethylene glycol or propylene glycol prevents the water in your radiator from freezing during cold weather.

This is an excerpt of a communication someone on BITOG had with Cummins Engine Company about 2-EHA and its impact on silicone seals/gaskets/hoses:

Coolant misinformation from a bitter grease-monkey - Bob Is The Oil Guy

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

The short answer? There are two kinds of coolant: orange stuff and green stuff.

If your car came with green stuff, use green stuff.

If your car came with orange stuff, use orange stuff.

Never mix orange and green. If you want to switch intentionally, flush the system before putting in the new type of coolant.

PS - Toyota uses green stuff, but they dye it red instead. Thanks, Toyota.

where do you get some FL22 other than the dealership?

No where that I know of and that shits expensive.

It's my understanding that this is the same as FL22:

Motorcraft Specialty Green Engine Coolant Part # VC-10-A2, which is available at pretty much any Ford Dealer (which is why I said above that Ford has now adopted Mazda FL22 coolant in pretty much every new vehicle it's unveiled in the last couple of years),

-And believe it or not, this is VERY close to FL22 if you look at the MSDS:

Beck/Arnley Engine Coolant/Antifreeze Part # 252-1001U (available at places like O'Reilly's, on Amazon and others). It's referred to as a concentrated green coolant that's actually listed as an OEM coolant for Mazda vehicles.


With that said, one can also go with Peak GLOBAL Lifetime Antifreeze & Coolant Liquid (if it just says PEAK and doesn't also have GLOBAL in the name, it's almost certainly a Dexcool clone containing 2-EHA like the others, so skip it), which is available at quite a few places, also, as it contains no 2-EHA, and no silicates or borates (Japanese manufacturers HATE silicates and borates in coolant). Believe it or not, both Menard's (it's like a Home Depot in the midwest) has this (and it's on sale RIGHT NOW for $7 per gallon for the 50/50 premix) and Walgreen's also carry this (yep, Walgreen's drugstore).

If you go with this, its good to a proper flush (to err on the side of caution, doing a proper, full flush is probably always a good idea anyways) until clear distilled water runs through the radiator, or even use one of the better flush machines at a shop, because if you do and save the documentation, Peak Global provides a lifetime warranty against coolant system failure/motor damage caused by the coolant itself.

I've heard very good things about the Peak Global Lifetime, but I still wouldn't trust it or any other coolant for a literal lifetime, and would stick the manual for coolant interval changes. Luckily, I can get the full concentrate for about $16 per gallon around here at independent places, while the Motorcraft Specialty Green (FL22 re-labeled) is $27 per gallon, and the FL22 is being sold by Mazda dealers for $30 a gallon (in truth, though, I'd still pay the higher price for either of these versus any crap with 2-EHA from the stores, since it's actually only going to be changed every 2 or 3 years, and I want peace of mind that my coolant gaskets and seals are not going to be warped/eaten/"attacked").

All the above come in full concentrate gallons or in 50/50 premix variations. So, unless a 50/50 premix variation is less than 50% the price of its full concentration version, you're almost always better off going with the full concentrate, and diluting it yourself with distilled water (and you can also control the ratio that way; i.e. 55/45, 70/30, 60/40, etc.).

Roto

the radiator hoses are EPDM rubber, if you have the car apart, the hoses are labeled.

actually with the rotary the big concern is the inner water seals, i am not sure what they are made from, but they are the important ones!

the early Rx8's used the regular green Mazda coolant, the switch to the FL22 was in 2006-2007 or so, if the car had the FL22 it should have a sticker somewhere near the fill cap.

in addition to the FL22, Mazda has a normal green coolant, which is different from the usual after market stuff.

the Mazda stuff seems pricey, but its undiluted, so you buy one gallon, instead of two for the "pre mixed" aftermarket stuff. so do the price shopping.

yep, mine has fl22 right on the cap. I used prestone 50/50 crap the last time i had to flush my coolant (when i installed my water temp gauge. Looks like i should get rid of it huh (bout time anyway, been about 2 years and an autocross season

I've read on some forums people saying Prestone Extended Life 5 Year/150,000 Mile (the yellow stuff) doesn't have 2-EHA, but carboxylate instead, and they are wrong, and you are correct -- it has 2-EHA, and it's right on the label. Even if they were correct, caboxylate is a form of 2-EHA, essentially.

my local mazda has fl22 for $24 (so ~50 for 2 gallons)... honestly I dont mind paying that for fluid that I change every 2 yrs

Poking around on the web, I found that pre-06 Mazdas came with a early P-OAT coolant, and FL-22 is the improved stuff:

To enhance service life, reduce waste material, and lower maintenance costs, a new long-life pre-mixed “FL22”
engine coolant is being introduced into mass-production for the models shown above.

It is recommended that FL22 coolant continue to be used for models originally filled with FL22 coolant from the
factory.
CAUTION: FL22 coolant is “pre-mixed” and must be added to the cooling system as is. DO NOT ADD
WATER TO FL22 COOLANT. Adding water will dilute the solution and lessen the effectiveness of
the coolant.
If coolant replacement becomes necessary for prior Mazda models (not originally filled with FL22 coolant), FL22
coolant can be used. If FL22 coolant is used for prior models, be sure to place the FL22 sticker on the reserve
tank or degas bottle to indicate FL22 coolant is being used.
NOTE:
• In the case of prior models, the coolant replacement interval is every five (5) years or 60,000 miles
(96,000 km).
• Six (6) FL22 stickers are included with each case of coolant.

Not very clear, but it's just another new type of coolant. Says here on the bottle, "ethylene glycol based.... 55/45 mixture recommended..... developed to provide corrosion and rust protection.....boiling point 270 degrees, freezing point -47 degrees. Ingrediants: Ethylene Glycol (107-21-1), Water (7732-18-5), Diethylene Glycol (111-46-6), Potassium Hydroxide (1310-58-3), Proprietary Inhibitors (NJTSRN 217).

oh ass, i missed this part .. damn so that means we are looking closer to $150 for a full coolant change?

The "Proprietary Inhibitors" language is what worries a lot of people who are concerned over the 2-EHA issue. It's one way that manufacturers proclaim they're merely protecting their formula from being copied, but many worry that it allows to much room for manufacturers to hide certain ingredients/chemicals/compounds from the consumer or end user.

Many times, a look at the MSDS will reveal some or all of those "proprietary inhibitors."

I don't believe it's ever been alleged that FL22 contains 2-EHA, having said that, and all Japanese manufacturers warn against 2-EHA in coolant.

http://www.bractwalls.com/user/image...antifreeze.pdf

above is a link showing that the prestone 50/50 uses 2EHA

Math ftw, S2 coolant capacity = 10.2qts = 2.65Gal lol

So I revise my above statment ... it would cost about ~$75 for a FL22 fill

btw question regarding flushes ... doesn't the thermostat prevent you from getting to the coolant that is in the water jackets?

Good find. Lol. With these engines we have to be more than careful...

No, there's a drain plug on the LHS of the engine.

Exact location shown in post #14 here: https://www.rx8club.com/tech-garage-...3/#post2550991

Search noob! :yelrotflm

Based on the no-phosphate content of FL-22, I'd waste another $3 and do a fill and drain with distilled water before final filling. Phosphate helps counter hard (mineral-filled) water from the tap.

Indeed. And perhaps the '06 change is a partial explaination for coolant seal failures in the 04/05 models. Perhaps too, the plastic-softening properties of 2-ETA come into play with coolant bottle failures and the tendancy of hoses to "weld" themselves to the plastic nipples on our radiators.

:dunno:

This issue may warrant a few lines in RIWWP's new owner's thread too.

Yep...agreed.

In fact, it's my opinion that it's better to even do a pure water fill after draining the old coolant, warm the motor (even drive it a bit), drain, and then repeat, to ensure as much as the old coolant is removed.

The pressurized flush machines are supposed to more efficiently accomplish this, and they use citrate-based cleansers with these machines to allegedly help dissolve deposits and build-up that a flush alone won't accomplish. Whether this really works that well or not, I do not know.

I spoke with a tech at one of the major companies that makes a lot of the coolants (chain store brand names and even manufacturer-branded ones), and he was extremely knowledgeable, and needless to say, the Dexcool issue is complicated.

One thing he mentioned that struck me is that many people would do well to make sure their radiator cap, which is a $8 to $12 part, is sealing properly, on a regular basis, and if not, it's money well spent to replace it with a new one, since air introduction into the coolant system is one of the main things that degrades the inhibitors & additives, and that can even alter the acidity (change the ph) of the coolant. Good advice!

FYI, I was just told by a tech friend (Ford dealer) that at least two Mazda dealers in my area no longer use the flush machines for coolant changes. He said they use the old school method, but wasn't told the official reason why.

Not sure if true or not, and I would never pay the dealership rate for a coolant change anyways (just my .02).

so my dealership not only stocked on FL22, but also the concentrated stuff (under the name Long Life Coolant as opposed to FL22's Extended Long Life Coolant). Just to be sure I double checked the chemical makeup and they were similar (none of the acid crap)

The existing FL22 that Mazda is using is all concentrated as is, and is a 2nd generation HOAT (hybrid organic acid technology). In other words, you must add distilled water to it. So, if you were striving for a 50/50 coolant-to-water mix, 1 Gallon of FL22 = 2 Gallons of coolant. If I'm wrong, someone let me know.

Also, Motorcraft Specialty Green Engine Coolant VC-10-A2 is the exact same thing as Mazda's FL22 (Motorcraft Specialty Green VC-10-A1 is the premixed stuff), and can be usually purchased for $5 to $7 less per gallon than Mazda FL22.

I've also found that dealers vary widely in price. Mazda dealers are charging anywhere from $23.xx to $30.xx per gallon of FL22 in my area, while Ford dealers are charging anywhere from $21.xx t0 $27.xx.

Peak Global Lifetime is good stuff, IMO, as it meets the ethyl glycol base requirement of Mazda, and has NO silicates nor borates (and it doesn't contain 2-EHA, either).

huh? the FL22 coolant from mazda is already a 55/45 mix

Ahhhh, I stand corrected. You are right.

I've been trying to digest way too much information too quickly.

The Motorcraft Specialty Green coolant (Ford re-labelled FL22) is probably the same, then?

I've been thinking about the coolant issue more and more with each passing day, and I've begun to wonder what cause & effect correlation, if any, there's been regarding catastrophic motor failures and coolant seepage/migration into areas it was never meant to travel.

I am aware of the age old adage that correlation does not equal causation, but does anyone have any relevant information to relay regarding the role that coolant may possibly played in the failure (whether compression or otherwise) of a rotary?

Hmmm a GM product that doesn't work!? Say it ain't so!

Just before my old engine was replaced by a new reman, I had begun noticing my coolant levels were dropping very fast and I was sure I didn't have a leak. My compression numbers were falling and the rear rotor had lower numbers probably due to coolant heat and consumption maybe. I was using cheap stuff...

Boom!

Just like that, we have our first anecdote from a long-standing member.

That's what I'm talking about!

I wonder what Takashi Yamanouchi's R&D crew and the other über-engineers over at Hiroshima have to say about this whole issue.

we will never know.

Probably, there are just way too many things involving engine failure; owner care, driving conditions, driving style, environmental conditions, damage to other important parts, types of fluids used, premix non premix, gas type used... And it goes on. I owned my car for only about 8k miles until I got a compression test, and there you go low compression. Thankfully I was under warranty, but I already knew that from the start. That's why getting a compression test on a rx8 before buying it is so important, more so if the car is no longer under warranty.

I have no idea how the previous owner drove the car, maintained it, or what fluids they used... For all I know they could have used the cheapest coolant and hence why my engine was consuming coolant. Maybe the silicone seals had been worn out by the coolant and high heat, but it's all speculation. I'll never really know, only Mazda who got my reman could possibly determine the reason for my engine failure.

After a week or 2 i flushed the coolant and use Prestone, my coolant bottle sensor fails.
Not sure if its just a coincidence.

100% agree. Great info here! More than just few lines will be added. I think all of this is going to be pretty critical.

I've been doing some more research, and the plot thickens.

Honestly, I've never come across a more confusing, convoluted topic dealing with maintenance fluids than coolant (motor oil doesn't even come close to this level of absolute insanity).

I will really make this short, and allow everyone to do their own research, b/c I'm don't even know what is what.

What I do know:

Japanese automakers recommend a HOAT (Hybrid Organic Acid Technology) coolant, which is essentially a 2nd generation OAT one. By the way, Dexcool was the original Organic Acid Technology coolant, and OAT was introduced as a means of getting a longer life from coolants - the organic acid, whether benzoates, sebecates or 2-EH/2-EHA would act as a long term corrosion inhibitor, and this would allow for the reduction of the silicates (or removal altogether) that we knew in the "old school green" coolant, with those silicates doing an excellent job of corrosion prevention, but only for 2 years max, before they would no longer be suspended in the coolant, or "fallout," and do things like clog the water pump and leave white, scaly buildup and gunk everywhere.

Since so many people failed to stay on top of the frequent coolant changes with "old school green" high silicate coolant, manufacturers were seeing a lot of major damage to motors and radiators and other components while the vehicles were still under warranty, and they did not like this.

Hence the birth of Organic Acid Technology, low or no silicates coolant.

What the Japanese automakers want in their coolants is:

1) NO silicates.

2) NO borates (not low borates, but NO borates, just like the silicates).

3) They DO WANT phospates (Japanese makers WANT phospates in the coolant, as this has something to do with the type of water prevalent in Japan, which has to do with corrosion prevention), and

4) NO, NADA, ZERO 2-EHA or 2-EH (this gets tricky; see below as to why).


Okay, so the Mazda, Toyota, Nissan, Subaru Factory Fill and branded coolants meet these requirements, except that Honda's coolant apparently may not contain the phospates desired under number 3 above (?). Some claim Honda coolant just doesn't contain phospates, while others claim it does (?). I don't have a definitive answer as to who is correct.

Also, Zerex's "Asian Coolant" meets all these requirements. It's made by Ashland Chemical, which is one of the biggest companies making many different labeled coolants, oils and other fluids.

Now for the tricky part. CCI is a company that makes a LOT of the Japanese OE coolants, under the various Japanese automaker labels (including, I believe, Mazda's FL22).

As an example of how tricky this gets, let's take Toyota's red-colored extended life coolant sold under Toyota's own name at their dealers: It definitely does not contain 2-EHA nor 2-EH (even this gets tricky; are these the same, and are some coolants that claim that they have "no 2-EH" such as Peak GLOBAL engaging in trickery, because they actually do have 2-EHA while only stating they don't have 2-EH??), BUT the Toyota label long-life coolant DOES contain sebacates!

Sebacates are another form of organic acids, similar to 2-EH and 2-EHA, and in fact, were one of the main organic acids composing - da da! The original version of DEX-COOL (back in 1995 when it was introduced, and when the sludging and eating-of-LIMs-and-gaskets-issue-surfaced).

Not only did the original DEX-COOL that was so hated and despised have sebacates, but it was believed by many and STILL IS that sebacates are just as bad, IF NOT MORE SO, than 2-EH or 2-EHA, regarding silicone gaskets, hoses and other rubber/silicone parts, as sebacate is known to degrade silicone and rubber.

And for the final mind-cluster bomb? Many coolants that are HOATS, advertising that they are either and/or both 2-EH and 2-EHA free, and that have phosphates (which is required by Japanese manufacturers), often have MSDS sheets that do not specifically list WHICH organic acid they contain, instead choosing to list them under as "proprietary inhibitors."

They list these as "proprietary" for the ostensible reason that they don't want competitors to know what additive packages they're using as anti-corrosive, but this allows them to hide what could be some frowned upon ingredients from public view (intentionally or coincidentally).

SO, that's what I know. The more I learn, the more of a total cluster this all becomes.

This thread makes me nervous. :suspect: Just a month ago I flushed and re-filled my cooling system with an OAT coolant...

The stuff I got is a ready-mixed own-brand sold by one of the major motor-accessory stores here in the UK (Halfords). Advertised as "silicate free" and "compatible with all vehicle manufacturer's colours". It also has a bunch of manufacturer approvals from Audi, Ford, GM, VW, Chrysler, etc.

I found that it is actually manufactured by a well-known oil company here (Comma), and from the info on their website I suspect it is the same as (or very similar to) their own X-Stream G30 product. Interestingly, their G30 itself is promoted as being based on BASF's Glysantin G30 formulation, which claims suitability for all Mazda vehicles.

I have sent them an email to find out whether it contains 2-EHA; but, until I get a negatory reply, it makes me wish I'd been prepared to wait the week it would have taken for some FL-22 to be delivered. :rolleyes:

i think all the OEM's have their coolants mixed in the US, same reason a lot of beers are brewed here, liquid is expensive to ship.

I'm going to go with Motorcraft Specialty Green VC-10-A2, because it's the same thing as Mazda FL22 and is a 2nd gen HOAT coolant.

It's actually 50% less than FL22, despite that it's a full concentrate (so 1 gallon equals two gallons of Mazda's FL22 since the FL22 is pre-mixed).

Peak GLOBAL (made by Old World Industries) claims it is "2-EH Free," but doesn't claim that it's "2-EHA Free" (call me paranoid or justifiably skeptical). Even if it's both 2-EH and 2-EHA "Free," Peak doesn't list what organic acid(s) they use on their MSDS, instead claiming it's "proprietary." So, it could be anything AFAIC.

This coolant shit has gotten waaaaay too complicated.

One thing I'm worried about;
"Use only when specified. Do not use this product in systems originally equipped with any green-colored, conventional engine coolant such as Motorcraft® Premium Engine Coolant, meeting Ford Specification ESE-M97B44-A, or with the yellow-colored, longer-life Motorcraft® Premium Gold Engine Coolant, meeting Ford Specification WSS-M97B51-A1, or with any orange-colored, extended-life engine coolant such as Motorcraft® Specialty Orange Engine Coolant, meeting Ford Specification WSS-M97B44-D"

Would this be a problem for us? Would a really good coolant flush negate this if it was a problem?

Those are good questions, and here's my take, FWIW:

A complete flush (whereby the system is burped, flushes with distilled water are used until clear, mostly clean h2o comes out, and possibly a citrate based cleaner is used (depending on one's predisposition to those), should ideally be done whenever replacing coolant, period, and especially when switching over to a different one in composition.

As for the recommendation against using Specialty Green (the really dark green, FL22 type coolant) in systems that were factory filled with Motorcraft® Premium Engine Coolant, meeting Ford Specification ESE-M97B44-A, that's because the latter is essentially "old school" green, with a relatively high additive packet of silicates, good for two years, and the former is silicate-free, instead being a HOAT. There could also be a risk of sludge-ing/gelling if the two are mixed in significant degree, and there'd definitely be a dilutive affect that would weaken the additives in the former if full flush was done.

The same is true if the vehicle was factory filled with Motorcraft® Premium Gold Engine Coolant, meeting Ford Specification WSS-M97B51-A1, or with any orange-colored, extended-life engine coolant such as Motorcraft® Specialty Orange Engine Coolant, meeting Ford Specification WSS-M97B44-D", but for different reasons.

The Premium Gold is essentially a Zerex G-05 type clone, while the Specialty Orange is a OAT (and dexclone), rather than a HOAT. So the dilutive affect from both the Gold and Orange residual in the system on the Specialty Green HOAT definitely remain, as does maybe the risk of sludge-ing/gelling?

worst part about doing a flush = finding storage containers for all the drained coolant / contaminated water lol

spent the weekend doing 3 total flushes of water. (Drain, Fill, Run car until thermostat kicks, let run for a bit, car off, cool down a bit, repeat). Then filled up with FL22. My FL22 concentration is a bit lower than stated on the bottle since a significant amount of water stays in the lines/engine when you do a drain. I guess we will see if I have any issues come winter time with freezing water.

You're probably okay especially if you had a factory fill of FL22 (denoted by sticker and on radiator cap).

FL22 actually has a genuinely long lifespan (conservatively 4 years-- many who are anal about maintenance still won't wait that long, though), and if did have FL22 factory fill, you can always top it off with some Motorcraft Specialty Green VC-10-A2 which is exactly the same as FL22 but is a concentrate (not pre-diluted).

yea like i said in a previous post i had put prestone in when i installed my gauges a few years back. glad I am back on FL22 after reading this stuff.

its my understanding that since coolant is alcohol based it can be poured down a drain unlike oils.