Exact Antifreeze Brand

[scottfab]

Well, I've seen/heard enough from many expert DIYs and pros to make a decision.
The weather here in the NW has been great lately so...
I'll be doing a bit of maintenance tomorrow and Dexcool is going back in. I think the green stuff would work fine too but the extra years of interval service is worth it to me. And I don't want to have to replace that expensive water pump again like in 98. I have seen and worked on at least 5 engines with blown head gaskets, non of which had Dexcool. At this point I think LT5 head gasket problems are unrelated. While Dexcool is more "environmentally" friendly that's not it. I am staying with it becase 11yrs of use and
I have no complaints. But then I followed Hib's recommendation on the flushing procedure so maybe I got all the old green crap out first, who knows.

[ZR1Vette]

What are those quotes from?

Comes from a tech article The Chemistry of Cooling Systems written by Larry Carley (interesting guy...extensively written on cooling to brake systems and "is recognized as one of the top automotive technical writers in his field. Carley started in this industry working as a mechanic in high school before earning degrees in both journalism and engineering. He has authored more than a dozen books and more than a thousand articles on automotive repair")

Here is another (brief) one from him which I think relates to this whole thread>>

Universal Coolants: The Ultimate Answer?

By Larry Carley, Technical Editor
For nearly a decade, vehicle manufacturers have been introducing and using a variety of extended-life coolants. The only thing these coolants have in common is that they all seem to differ in formulation and color. There are orange coolants, green coolants, blue coolants, red coolants, yellow coolants, even pink ones. The proliferation of different coolant types has created a great deal of “chemical confusion” with motorists and technicians about what type of antifreeze should be used to top off or refill late-model cooling systems.
We’re not going to summarize the whole laundry list of OEM coolants and colors here except to say that each vehicle manufacturer has their own unique coolant specifications based on corrosion protection requirements, service life and chemical compatibility. These requirements are usually spelled out in the vehicle’s owner’s manual, and/or a decal or label on the coolant reservoir. It’s important to always use the coolant chemistry recommended in the vehicle owner’s manual. For example, Ford and Chrysler specify hybrid OAT-only coolants.
You can’t go by the color of the dye in the coolant because two coolants with similar colors may have different chemistry, and two coolants with different colors may have similar chemistry. What’s more, colors can change if somebody tops off the system with a different coolant.
The more we get into the specifics of each type of coolant, the more confusing the whole discussion becomes - so we’re only going to tell you what’s really worth knowing with respect to the different types of antifreeze.
There are essentially three basic types of coolants:

• Traditional North American “green” antifreeze, the original “universal” formula that everybody used until the introduction of today’s extended-life coolants. The fast-acting silicate and phosphate corrosion inhibitors provide quick protection for bare iron and aluminum surfaces, and have a proven track record of providing trouble-free service in virtually any vehicle application (domestic, Asian or European), assuming the chemistry is correct. For example, OAT coolants should not be used in a vehicle that specifies the use of a hybrid OAT coolant. Again, always defer to the owner’s manual. But the short-lived nature of the corrosion inhibitors means this type of coolant should be changed every two to three years or 30,000 miles (though some products now claim a service interval of up to 50,000 miles with improved chemistry).
• OAT-based extended-life coolants. OAT stands for Organic Acid Technology, and includes such ingredients as sebacate, 2-ethylhexanoic acid (2-EHA) and other organic acids, but no silicates or phosphates (except in the case of Toyota’s pink extended-life coolant, which adds a dose of phosphate to its extended-life OAT-based antifreeze). OAT-based coolants are usually (but not always) dyed a different color to distinguish them from traditional North American green antifreeze. GM’s OAT-based Dex-Cool is orange. Volkswagen/Audi uses a similar product that’s dyed pink. But Honda has an extended-life OAT coolant that is dyed dark green and does not contain 2-EHA.

The corrosion inhibitors in OAT coolants are slower acting but much longer-lived than those in traditional North American green coolants. Consequently, OAT coolants typically have a recommended service life of five years or 150,000 miles.
OAT corrosion inhibitors provide excellent long-term protection for aluminum and cast iron, but may not be the best choice for older cooling systems that have copper/brass radiators and heater cores. It depends on the formula.
· Hybrid OAT coolants, also known as “G-05.” This formulation also uses organic acids, but not 2-EHA (different organic acids are used). Hybrid OAT coolants add some silicate to provide quick-acting protection for aluminum surfaces. Silicate also helps repair surface erosion caused by cavitation in the water pump. Hybrid OAT coolants are currently used by many European vehicle manufacturers as well as Ford and Chrysler.
Still Confused?
Okay, so there are a bunch of different coolants in today’s vehicles. The question is, which type of coolant should you recommend to top off or refill a customer’s vehicle?
The “safe” answer is the type specified by the vehicle manufacturer. But practically speaking, shops don’t have the shelf space to stock different coolants for each different make of vehicle.
One thing the aftermarket has always been good at is consolidation, and today’s coolants leave plenty of room for that. Recently, many antifreeze suppliers have introduced “universal” or “global” one-size-fits-all coolants that are claimed to be compatible with any new vehicle cooling system as well as older vehicles.
The basic idea behind universal coolants is to eliminate all the confusion about colors and chemistry and have one basic product that works in any vehicle regardless of year, make or model. What could be simpler?
Not all antifreeze suppliers buy into this marketing philosophy, so you’ll still see the three basic types of coolant being marketed: traditional green for older vehicles and budget-conscious motorists who want the least expensive product on the shelf, an extended-life product that is compatible with Dex-Cool and other OAT-based coolants, and a hybrid OAT for late-model Ford, Chrysler and European vehicles that specify G-05 coolant.
But for those who offer a universal “all makes and all models” kind of product, the advantages are obvious: one or two SKUs to provide full coverage (full-strength antifreeze or 50/50 mix), less shelf space needed to stock the product, and most importantly, no confusion over which product to use in which application.
Makers of universal coolants say their products are formulated to be compatible with all cooling systems (foreign or domestic) and all coolant types (traditional green, OAT and OAT-hybrid with silicate).
The new universal coolants use unique OAT-based corrosion packages with proprietary organic acids (such as carboxylate) to provide broad spectrum protection.
When a universal coolant is used to top off a cooling system that already contains an extended-life OAT or hybrid coolant, the service life is unaffected. It remains five years or 150,000 miles. If a universal coolant is added to an older vehicle that has traditional green antifreeze in the cooling system, the service interval is also the same as before: two to three years or 30,000 to 50,000 miles.
If a cooling system is being refilled with a universal coolant, the cooling system should be flushed to remove all traces of the old coolant. This is necessary to remove contaminants and to maximize the service life of the new coolant. If only the radiator is drained, up to a third of the old coolant can remain in the block.
If the old coolant is traditional green coolant, the new universal coolant will be diluted and won’t be able to extend protection much beyond that of the original coolant.
One very important point to keep in mind here is that universal coolants and extended-life coolants are not lifetime coolants. The corrosion inhibitors in all types of coolant eventually wear out and must be replenished by changing the coolant. Leave the old coolant in too long and the cooling system will experience corrosion problems.

[scottfab]

Wow, that's some good stuff. I expecially like the note about completely flushing the old stuff out, corosion caused by leaving a coolant in too long and my favorite, the random mixing of coolants and it's effect on coolant life.

I'm definitely saving that write-up.
Thanks for posting.

On another note, some very good photo's have shown up on blown head gaskets and they look exactly like ones I've taken out of several cars over the years. Oh, and these had green stuff in them. Look carefully and zoom in. The corrosion is there on the photos. The same kind of corrosion I've seen on failed head gaskets using the green stuff.
http://forums.*************.com/c4-zr-1-discussion/1256561-would-you-believe-coolant-causes-head-gasket-failures.html

http://forums.*************.com/search.php?do=process
Now here is a new question. Does anyone know of any LR5 which has blown a head gasket that was using the green stuff?
Is the OAT based coolant at fault?
Or is it contaminated coolant?
Or is it coolant that has lost it's corrosion protection?
Or abuse (overheating)?

One thing I'd like to do is get hold of some new head gasket material
and soak it in OAT coolant to see what happens. Anyone know where a new but damaged gasket exists for this?
Scott

[jonszr1]

scott if you would like to do this i will donate 1 brand new gasket to try to find out once and for all if it is the coolant or just the gasket . pm me your address and i will have one sent to you .brad

[ZR1Vette]

Just found this... another vote against Dex Cool and Prestone Extended Life coolants>>>

Dave Porter, long time Healey nut and general all round good guy, suggested that I take some time to enlighten readers as to the finer points of antifreeze which, like most things in our world, has become a much more complex subject that it was just a few years back. He pointed me to an article on the Master Technician site by Bob Freudenberger which surely emphasized that!!
In the old days, well since WWII, all we had was the old reliable “green stuff”. (Prestone used to dye theirs yellow-gold but it was the same stuff to all intents and purposes) “Green stuff” consists of about 95% ethylene glycol and the rest is corrosion and erosion inhibitors like silicate phosphate and tolytriazole, sodium benzoate which is an organic acid that is also added to Coke (the drinking kind), some dyes and 1 or 2% of water. This brew works very well although over time the corrosion inhibiting properties deteriorate over time. So you should do a flush and refill every 3 – 4 years.
Unfortunately many of today’s manufacturers and less than enthused about these concoctions and all manner of new and fancy antifreeze mixtures have appeared on the scene in the last few years.
These of course include GM’s DexCool which has gained something of a bad reputation and at last count there were at least 14 class action lawsuits filed in state and federal courts throughout the U.S. representing GM vehicle owners angered over their experience with this product.
Dexcool is based on OAT (Organic Acid Technology), and its additive package according to GM’s literature can keep corrosion away for up to 150,000miles. It seems that the big problem is that Dexcool doesn’t like air. Everything is hunky-dory just so long as the cooling system remains completely full of coolant but introduce some air and things go seriously pear shaped and the additives in these OAT type antifreezes produce a guckey goop which clogs coolant passages and generally creates havoc in the victim’s cooling system.
Additionally, one of DexCool’s ingredients is sodium 2-ethyl hexanoate which is a “plasticizer” . Plasticizers soften plastics which, as you can imagine, isn’t exactly ideal for use in engines which have water heated intake manifolds made from the plastics that these ingredients soften.
There are other OAT based antifreezes out there and these include Prestone’s new Extended-Life gold is and Wal-Mart’s Super Tech brand. I would suggest avoiding the use of these in any vehicle. However…I digress.
So what should one use for antifreeze in a Healey? The short answer is “The green stuff and not too much of it”.
Based upon the number of questions posted on the Healey newsgroup about overheating problems this does seem to be a major issue with Healeys. I distinctly remember participating in the rally during an event in Tahoe a few years back during which the last section was a long climb in the desert heat. The further we climbed up the slope the more the side of the road was littered with steaming Healeys. At one “Kodak Moment” vantage point it was difficult to find a place to pull off to take a photo!!
It has been my experience that if the cooling system of a Healey is in good condition overheating is not a problem and as many of us don’t drive our cars in the winter here is something to consider.

Water Ethylene Glycol 50/50 mixFreezing Point 32F 8.6F -36FBoiling Point 212F 387F 225FSpecific Heat 1.00 .57 .81Thermal Conductivity .60 .25 .41
I’m no thermodynamics specialist but as I understand it the specific heat value is a reflection of the amount of heat a given weight of fluid (coolant) can transport. Now if the 50 / 50 water-antifreeze mixture in your cooling system can only carry 80% of the energy pure water can it seems obvious to me that I would want water and just water in my cooling system. Sure it may boil at a 13 degree lower temperature but if the system is working 20% better it probably won’t ever get that hot.
There is no question that if you live in a part of the world where the temperature drops significantly below freezing on occasion you need to have some type of anti freeze protection in your vehicle’s cooling system but this sure isn’t required in summer when overheating is the “issue of concern”.
One consideration of course is that pure water doesn’t provide much in the way of corrosion protection, but you can buy straight corrosion inhibitors to add to your coolant to solve that problem. One source is:Here and I’m sure thare are plenty of others.
The reverse situation also applies. At the beginning of the cold weather here in the Great White North most auto repair shops get a number of customers coming in complaining that their heaters aren’t working. The most common diagnosis is that the heater core is plugged and the customer has to either put up with freezing feet for the duration of the winter or part out with a hefty wad of dough to have the core replaced. The fact is that in a fair percentage of cases the problem could be resolved by just checking and adjusting the percentage of antifreeze in the cooling system. We used to check the antifreeze concentration as part of a regular service and many was the time when we would discover that the cooling system had more than 70% antifreeze. Definitely a case of more is not necessarily better!!

[tomtom72]

If we just soak the gasket do you really think that will tell us much? Not trying to be a wise a$$. I'm just saying that if you soak anything long enough, even gasket material, in plain tap water you might see some swelling just from absorbtion, no??? I mean I don't know how much swelling, but osmosis has to happen, right?

I tend to think that heat + pressure + an open deck block have an influence on what different coolant formulations wiill do to an LT5 head gasket...????

[tomtom72]

That last post is great Mike, so was the other write up from that professional!!!

I base my mix of GM 1825-M (local chevy dealer makes me buy it by the case) coolant to distilled water, and two bottles of water-wetter. If you follow the alternate W-W instructions it say to try not to exceede a 20% anti-freeze concentration + water + W-W. I'm not absolutely sure about the W-W 20% number. I use 30% anti-freeze because of where I live & the fact that my rented garage is unheated & after the 1st salting the Z stays locked up. However, I use steam distilled water as my base, add the GM old school stuff and then 2 big bottles of W-W and dump that stuff every two yrs or about 10k miles. I flush till clear w/reg water, then flush using 12 gallons of steam distilled water, then mix up the new batch & do the T-stat at that same 2 yr interval.


Tom

[scottfab]

Brad, contact me at scotfab@aol.com for an address.
I would propose to slice up the gasket into several pieces and run a separate study on each. Details of which I will post later.
There has been detractors already about the validity of such a test.
The point will not be to try to exactly duplicate the LT5 of a Healy environment and in fact any result that shows no swelling will be suspect and subject to massive attacks by those that have been scared into using the green stuff.
The main point on this experiment will be to see if swelling occurs at ambient temperature over a period of time. Other experiments could follow……
Like our new Vice Pres let me say that again.
Other experiments could follow……
Here are the setups I would propose:
1. new Dexcool at 50%
2. 4 yrs old Dexcool 50% (out of my ZR1)
3. Green stuff at 50%
4. 2yr old Green stuff at 50% (from my Explorer)
5. Water alone

Measurements would be visual using a macro lens and camera.
Containers will be sealed and washed jars. Samples would be completely submerged.

We will all have to make up our own minds on coolant (obviously) but I for one would like to see more data and less speculation. If Dexcool is really the “evil empire” then lets find out.

All info I have seen on the “14 class action suites” has been about Nylon/Silicone type gaskets that are used on 2005 and newer GMs.

[TommyL]

Dex-Cool has definately been connected to Gasket issues. I was informed by my local GM dealership that Dex-Cool has been connected to head gasket issues in many of their vehicles. The 4.3 V6 has had this issue in many of their vehicles for a few years when they first introduced Dex-Cool. After talking to the "Technician" for a bit about this, it was sugested that I change the "Dex-Cool" coolent every 2 years in my 2002 Olds Auora as a preventative measure against "possible" gasket issues. He also made the comment "not to put it into any vehicle that didnt come with factory fill Dex-Cool". I bought the old fashioned green prestone and use that in my Z...I think the Dex-Cool can cause issues so I personally will avoid it unless it is recommended for newer vehicles. If it aint broke....why try to fix it?

[Aurora40]

Originally Posted by ZR1Vette

If a cooling system is being refilled with a universal coolant, the cooling system should be flushed to remove all traces of the old coolant. This is necessary to remove contaminants and to maximize the service life of the new coolant. If only the radiator is drained, up to a third of the old coolant can remain in the block.

That's actually exactly why I don't like flush products, nor flushing with a garden hose. You pump some corrosive flush product, or some mineral filled hose water through the engine, you can bet there will be a lot of it caught in the block, heater core, etc that you will never get out. So that crap will be compromising the mix ratio and integrity of the new coolant you put in. How much antifreeze do you need to end up at 50/50? Well it depends on how much water is trapped in the block.

You can take the published capacity, add half that much pure antifreeze, then fill the rest up with water. That assumes the capacity is correct, and then the water trapped plus the water added will be equal to half of that. But I can't say I'm a fan of that.