Exact Antifreeze Brand

[Hammer]

OK everyone, I am getting ready to flush my cooling system, install new radiator, Samco hoses and thermostat. I will flush the system with distilled water and add green antifreeze and water wetter.

Now

With all the posts on antifreeze, green, silicated, and so on, what I would like to know is what BRAND, color bottle and so on have you used successfully to avoid the head gasket failures.

Thanks

[Peaven]

OK everyone, I am getting ready to flush my cooling system, install new radiator, Samco hoses and thermostat. I will flush the system with distilled water and add green antifreeze and water wetter.

Now

With all the posts on antifreeze, green, silicated, and so on, what I would like to know is what BRAND, color bottle and so on have you used successfully to avoid the head gasket failures.

Thanks

John, I use Texaco Anitfreeze Coolant...ingredients are as follows: Ethylene Glycol, cps#222353. It's a plain black gallon bottle.

That's it...pure old school green stuff. Picked it up at Autozone. So far so good for me, I'm getting ready to do a flush and reload of mine this week. Don't forget to add a bottle of water wetter!

[Hammer]

John, I use Texaco Anitfreeze Coolant...ingredients are as follows: Ethylene Glycol, cps#222353. It's a plain black gallon bottle.

That's it...pure old school green stuff. Picked it up at Autozone. So far so good for me, I'm getting ready to do a flush and reload of mine this week. Don't forget to add a bottle of water wetter!

Got a bottle sitting on the shelf ready to go.
Thanks

[jonszr1]

what chemical is the bad one that causes all the problems. i hear they are combining stuff . amodified verson of that evil orange . anyone know about this.?:icon_scra

[GOLDCYLON]

what chemical is the bad one that causes all the problems. i hear they are combining stuff . amodified verson of that evil orange . anyone know about this.?:icon_scra

Dexicool

[tomtom72]

what chemical is the bad one that causes all the problems. i hear they are combining stuff . amodified verson of that evil orange . anyone know about this.?:icon_scra

Jon, I don't know all the tech stuff but this is what I know for sure.....I think!:???:

Silicated coolant (ethlyene Glycol based coolant), other wise called green stuff, is the old fashioned toxic stuff. The color don't mean much except that most brands that use silicates as the primary corrosion inhibitor are green in color and are ethylene glycol based. Remember the color is not a fail safe test of the active chemical used. Ya gotta read the label completely as sometimes it's not listed in ingrediants but under medical remedies on the label, aka the Material saftey data listing sheet.

GM 1825-M is an ethylene glycol based coolant, and is listed in the 90's owner's manual as the correct coolant to be used. Sorry I only own one Z so that's all the info I got on what the owner's manual says about coolant. That coolant is green but it's active corosion inhibitor is a silicate & it's a glycol based coolant...that's the important part. GM still sells the stuff I get mine from P & G chevy because the local don't carry it & laughs at me alot!

The newer coolants are mostly an organic acid based coolant. They work differently than the silicated glycol based stuff. You can't mix the two as the reaction produced by mixing the two is a "jell". N/G big time! I believe the inhibitors and the coolants bear the words "organic acid based" or POA, or OAT....they stand for something but I don't know what...but I know it ain't glycol based silicated coolant!

JMHO on all this chem engineer speak....color don't mean anything. We need a glycol based silicated coolant. Acid bassed coolant ( non-silicated & non-glycol based coolants ) will cause head gasket failure in our LT5's...that bites where I come from! If I read a label and don't see the word silicates or siliacated salts and glycol based, I don't buy the stuff. I buy mine from the mentioned dealer on line. I know it's a drag but at least I know for sure I got the right item because the label says "1825-M" glycol based silicated coolant & Mr Goodwrench is smilin' back at me!;)
Oh by the way, Toyota still uses glycol based silicated coolant!
:cheers:
Tom

[Hammer]

Well everything is now done. Went pretty good and I ended up spending some time cleaning afterwards. The engine bay (underneath) was filthy from 16 years of driving and not taking care of the car.

I ended up using antifreeze from NAPA, it has the silicates (says it on the bottle) and meets the 1825-M spec. The hoses, radiator and thermostat went on without a hitch and the car runs much cooler now.

A word on the thermostat, I used a NAPA #124, it is a reboxed 180d STANT and the gasket is on it. When you go to install it, use a putty knife on one side and the bracket that attaches it to the frame on the other, to hold it in while you screw the t-stat housing down, pull them out and your done (after tightening the housing of course). Works great.

[tomtom72]

Hammer that's a cool idea on the T-stst install!:thumbsup:

Oh also I have another source for a T-stat if anyone is interested. Go to the autozone site and they have one that "fails open" if it has an issue. I tried it last yr when i did my cooling system clean up and so far it works real well.

:cheers:

[Aurora40]

Silicated coolant (ethlyene Glycol based coolant)
Hey Tom, just to be clear, Dex-Cool, G-05, etc, are all ethylene glycol based and all quite toxic. Generally the only stuff that isn't is the low-tox products like Prestone's low-tox coolant, and the Sierra brand. They are propolyne glycol which is much less toxic. They generally are a silicated coolant too, but if you spill some it probably won't kill anything.

In a car that doesn't really need max cooling, that stuff is pretty decent. I used it in an older car that sat out because if it ever spilled anything and killed some dog or cat or something I would have felt pretty bad.

I got my t-stat from ACDelco, it was only like $6. Is this NLA now too?

[jonszr1]

thanx for the info on the silicates. i also heard that distilled water is not cool either that its more corosive than soft water which is what they say should be added. I reaDIT IN ONE OF THE CAR MAGS ANYONE KNOW ABOUT THIS

[Aurora40]

Distilled water is what you want. It being corrosive sounds like BS.

[jonszr1]

thanx I thought so too just wanted to ck . have a great dAY:-D

[cuisinartvette]

what chemical is the bad one that causes all the problems. i hear they are combining stuff . amodified verson of that evil orange . anyone know about this.?:icon_scra
sounds like crystal meth.

[EuroPete]

Hi guys, do you know if Dex Cool can damage the gaskets or corrode the radiator? I've been recommended this coolant fluid but if you type "dex cool gasket problems" on Google you find lots of articles related to it.

Just got a '90 red/red 27,000 mile ZR-1. I'll introduce myself and hang some pictures ASAP.

[bradslt5]

pete,DO not use dexcool only use the green stuff that has 1825 gm spec on it .the other stuff will eat our head gaskets

[EuroPete]

pete,DO not use dexcool only use the green stuff that has 1825 gm spec on it .the other stuff will eat our head gaskets

Can you recommend any brand name or product for ethylen glycol coolant fluid GM compliant? In my country they know nothing about this, they only have AC DELCO Dex Cool so I'm afraid I'll have to order it from the US.

Thank you Brad!

[bradslt5]

pete do you have a dhev dealership over there ? if so order the 1825 from them . make sure that they understand that you want 1825 and NOTHING ELSE . good luck and have a great day

[EuroPete]

pete do you have a dhev dealership over there ? if so order the 1825 from them . make sure that they understand that you want 1825 and NOTHING ELSE . good luck and have a great day

Brad, the problem overseas is that American car parts stores are really rare and they're not expertised enough in certain aspects. I think I'll call my friend Mark from Wisconsin tonight so maybe he can get this antifreezer immediately.

Anyway, thank you very much mate :-D

[gbrtng]

pete,DO not use dexcool only use the green stuff that has 1825 gm spec on it .the other stuff will eat our head gaskets
Brad, please cite your source for this eating head gasket "problem".
That's a new one on me. FWIW, I converted to Dexcool in 1997 by completely flushing with distilled water - did 4 fill and drain cycles - then filled with Dexcool. No problems 11 years later. Instead of google, check out www.bobistheoilguy.com and study the antifreeze forum; there are several industry gurus lurking. And, the green stuff was all that was available in 1989 when out cars were introduced; the non-phosphate stuff came out two years later in the Saturn line.

[EuroPete]

That's a new one on me. FWIW, I converted to Dexcool in 1997 by completely flushing with distilled water - did 4 fill and drain cycles - then filled with Dexcool. No problems 11 years later.

gbrtng, what did you do exactly? Fill the full cooling circuit with distilled water and empty it four times? Then, filling it with Dexcool completely, right?

Seems to be an easy procedure, it's only a matter of spending around 50 liters of distilled water, isn't it?

[bradslt5]

Brad, please cite your source for this eating head gasket "problem".
That's a new one on me. FWIW, I converted to Dexcool in 1997 by completely flushing with distilled water - did 4 fill and drain cycles - then filled with Dexcool. No problems 11 years later. Instead of google, check out www.bobistheoilguy.com (http://www.bobistheoilguy.com) and study the antifreeze forum; there are several industry gurus lurking. And, the green stuff was all that was available in 1989 when out cars were introduced; the non-phosphate stuff came out two years later in the Saturn line.my source is right in your area, New braunfels, do you know corey henderson? i have 2 zr1s one of which i bought that had dexcool in it , 3weeks later poof head gasket went . there are many here that have had this happen to there cars . so you have run a zr1 for 11 years with dexcool in it ? the head gaskets in a zr1 are made from different material than other gaskets . at least thats what i have been told . i just know in my cars i will only run the stuff that is gm spec1825 for our engines . changing head gaskets in these motors is not an easy deal . 400 in tools pulling the motor etc . so to me why take the chance . dexcool is not gm1825 spec and thats good enough for me.

[bradslt5]

gbrtng, what did you do exactly? Fill the full cooling circuit with distilled water and empty it four times? Then, filling it with Dexcool completely, right?

Seems to be an easy procedure, it's only a matter of spending around 50 liters of distilled water, isn't it?pete the choice is yours but if it were me i would only use gm spec 1825 . get ahold of jeffvette here on this forum he is one of the most knowledgable people on our cars ask him and follow his suggestion. that is the best advise i can give you . good luck in whatever you decide .he is pnwzr1 in the links section

[scottfab]

Does anyone have actual evidence that the coolant Dexcool caused the head gasket problem? Pictures maybe? I am curious about erosion vs other failure.
I have had Dexcool in mine from 98 on. I’ve swapped it out twice and it is due again now.

[jonszr1]

scott , i would get ahold of jeffvette aka jeff flint @pnwzr1, since he is in your area and discuss your dilema with him . he know our cars as well as any one . as for scientific proof i don t have any . i have just heard of a lot of problems when using dexcool , so i decided to just not take the chance, having allready seen a head gasket failure in on a 90 zr1 i used to own . the choice is yours

[scottfab]

ah, so Jeff is the expert on this. Ok, I know him well and in fact helped him with his first plennum pull back in the 90s. Sure sounds suspiciously like regular old head gasket failure though. I’ve done many in the past on various vehicles. Of course non of these have had Dexcool in them so I can’t blame it on Dexcool. Turns out head gaskets can fail from other causes. Most that I’ve done show deformation off the gasket at the weakest point. In fact only one of those that I have ever replace did not show this deformation.
Your right about one thing there for sure. It is my choice and until I see some evidence of corrosion I’m not likely to stop using the orange stuff. It last longer and is easier on water pumps.
At this point it just seems like conjecture on root cause. I’d be more inclined to think some sort of partial detonation event would be the cause. Obviously a full detonation event would be catastrophic but a late detonation (very close to TDC) would seem to fit the profile of deforming the gasket.

[scottfab]

BTW Jeff's email is jeff2577@yahoo.com or he can be reached at pnwzr1@pnwzr1.net
The Address given before was bogus.

[Pete]

Do you guys know if Dexcool lasts as long as the Green stuff.

All i know is i looked at a friends 18 year old car with 50k miles with green stuff and my own 14 year old 60k mile car they still look green like they were just changed.

I have 2001 Caddy with 50k miles with Dexcool looks like sh!t.
If 50k is considered extended life then it's garbage,now i know why the factory warranty is only good for 36k miles
If it looks like that at 50k what's it gonna look like at 100k.
Extended Life my a$$, just a sales pitch from GM.

And soon you will tell us McDonald's has the best burgers.:)

I'd like to see 15yo Dexcool in your car.

I'll stay with the green stuff.

Pete

[BLACK90ZR1]

It's not a ZR1, but the owners manual for my 2005 Impala says to use a one half "clean drinkable water" and 1/2 DEX-COOL solution. That's the first time that I have seen "clean drinkable water" specified.

[jonszr1]

BTW Jeff's email is jeff2577@yahoo.com or he can be reached at pnwzr1@pnwzr1.net
The Address given before was bogus.sorry if i didnt give the right address i dont do business with him and was just trying to direct him to the best person in his area that might help him

[scottfab]

Has anyone replace a head gasket in a LT5 motor that was using
the green stuff?? And if so what did you see?
Do the head gaskets simply not fail in a motor with the green stuff?

[ZR1Vette]

Probably to add to the coldrum... in my research and in many discussions with ZR-1 owners and a certified LT5 tech went with Prestone Extended Life 50/50 (thus no issue on what water to use for full concentrate coolant :mrgreen: ) Coolant...meets the GM 1825-M and exceeds ASTM D3306:
The coolants governed by this specification are categorized as follows:

Coolant TypeDescriptionIEthylene glycol base concentrateIIPropylene glycol base concentrateIIIEthylene glycol predilute (50 vol %)IVPropylene glycol predilute (50 vol %)
and ASTM D4985:
Covers the requirements for low silicate ethylene glycol base engine coolants

and the Prestone Extended Life has NO Silicate, phosphate, borate, and nitrate. Specifically recommended for aluminum block/head engines. Stuff is a little pricey compared to what else is on the market...but $$ is all relative.

[scottfab]

I had a gallon of milk go bad the other day..... Looked great but was still bad :)
Not sure if looks of green or orange are definitive. I have used looks on Dexcool up till now thinking if there is no sign of sludge then…ok. Now I am not sure. If the orange stuff turn acidic over it’s design life in the LT5 then maybe eating of the head gasket is possible.

I am amazed that one would ever leave green or orange stuff in a car for 15 yrs.
I don’t know of any fluid that would last that long in the LT5.
Being objective though, I think the orange stuff is suppose to last longer, like 5yrs
or so. The green stuff forms tiny crystals in it when it gets old. These take out the water pump. The orange stuff forms a nasty growth in it (sludge) if it gets contaminated
(or maybe old too?). The recent conjecture is that it eats (dissolves) the head gaskets
in the LT5. If actually true then I'll be getting off the Dexcool. If not provable then I'll stay with it and eat my burgers at Burgerville. Others can stay with green McBurgers.
Still others can stay with clear water and “water wetter” and eat at Wendy’s.

[jonszr1]

scott , you might also want to contact mark haibeck. he does alot of deep reasearch into things like this . he might be the best person to find the truth or lack of on the dexcool issue .you can find his web page by going to the links sec of the registry . hope this helps .

[scottfab]

Thanks for the lead.
I checked Mark's site. I only found how to fill and details on what his shop performs on a routine maintenance.
http://www.zr1specialist.com/HAT%20Web/articles/filling%20coolant.htm
http://www.zr1specialist.com/HAT%20Web/services/pm.htm
I wrote him a note on this topic.

[Z51JEFF]

I just flushed mine,used the Napa stuff,all I needed to see was the 1825 spec,good enough for me.As far as the Dexcool being a problem,all I needed to hear was head gasket failure and that did it for me.Is Dexcool bad for the system?I cant speak from experience but I wont put it in my car.

[tomtom72]

FWIW, the only time I saw a thread about antifreeze and head gasket failures with pictures was over at CF in the ZR-1 section. The author of the thread was "MrCrowley", aka Mike Ebert of EES (Ebert's Engine Service, EES.com). He started the thread to show us what the failure looks like. If I remember correctly it was an issue with the gasket material being delaminated from the exposure to the newer generation of Organic Acid Bassed coolants.

A search over there may turn up the thread, but I've heard that the archives were toated when they got new servers.:dontknow:

:cheers:
Tom

[Aurora40]

and the Prestone Extended Life has NO Silicate, phosphate, borate, and nitrate.
This is because it is an OAT type coolant just like DexCool. The fact that it has no silicates is not, in my opinion, a good thing.

I really don't see the point with going with something other than a proven/recommended silicated anti-freeze. The longer change intervals of DexCool don't really apply if you are putting it into a system that already has silicates in it. I don't think even a flush would work because the silicates stick to stuff (which is how they work, apparently). So with DexCool you'd want to stick with conventional change intervals anyway.

Unless you are trying to go with more water % with something like water wetter, why not just make the safe play with silicated coolant. It works great, I'm not aware of any downsides other than it becoming harder to find and a bit pricier.

Lately I've actually thought of going to something "friendly" like Sierra or something. Mainly because they are a traditional silicated coolant and are cheap. Plus I won't be as worried about small leaks, etc. The only difference is they are propylene glycol vs ethylene glycol. It apparently transfers heat slightly less efficiently (though water does the bulk of that), but is factors of 10 less toxic.

[ZR1Vette]

Bob.. I am willing to look at all views and learn... this coolant issue is confusing at best. To wit... GM 1825-M notes no silicates "GM says getting rid of traditional silicates helps to extend the life of the water pump" and " ethylene glycol antifreeze that contain a corrosion inhibiting chemistry that uses carboxylate organic acids instead of the silicates, phosphates or borates"

Thus when I talked to the Prestone tech folks this is what the Prestone Extended Life coolant does (I just used the 50/50 mix from them to eliminate the issue of what water additive is used)

If I am going down an incorrect road folks... let me know.

[jonszr1]

so if i am reading you right you changed over to the new stuff . one ? how well did you flush the system before putting in the new stuff .i have heard that problems can develope if you dont flush the system really really well. did the presone people share that with you. did you ask about potental problems in changing over ?

[Aurora40]

Bob.. I am willing to look at all views and learn... this coolant issue is confusing at best. To wit... GM 1825-M notes no silicates "GM says getting rid of traditional silicates helps to extend the life of the water pump" and " ethylene glycol antifreeze that contain a corrosion inhibiting chemistry that uses carboxylate organic acids instead of the silicates, phosphates or borates"
What are those quotes from? The actual GM 1825M spec? The coolant listed in your FSM, #1052753, is a silicated ethylene glycol coolant. They were called "low silicate" formulas back then, but are definitely of the silicated variety. Not an OAT coolant.

Also if I'm not mistaken, Prestone's Extended Life coolant does not meet the GM-1825M spec. I believe only their "regular" coolant does, though I don't know if you can even find it anymore.

I also could be wrong, but I do not believe GM has ever recommended using DexCool in a vehicle that was not designed/originally filled with it.

[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/c4-zr-1-discussion/1256561-would-you-believe-coolant-causes-head-gasket-failures.html)

http://forums.*************.com/search.php?do=process (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 (http://www.griotsgarage.com/search.jsp?searchtext=11181) 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!!!:thumbsup:

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.

:cheers:
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]

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.

[TommyL]

If the vehicle is driven in summer months only a 50/50 raitio is not needed...infact less antifreeze is better for cooling. A 50/50 raitio is recommended for cold weather driving but less antifreeze is recommended for summer cooling and lubrication of the pump.....less antifreeze and more water = better cooling. I use a 50/50 mixture beacuse you are correct in that some water will still be in the block so the end mixture is likely about 40/60.

[scottfab]

Oh boy, this is great. An actual dealer that will corroborate the story of head gasket failure due to or “connected with” Dexcool. Can I get the name of the dealer? I won’t mention where I heard it just confirm the issue with the 4.6 V6. The dealer is in Ontario?
I just want to nail this down so that I might convert back to the green stuff. Or if the issue is still related to the nylon/Silicone type gaskets then I will report on that.

[DMark]

This is the reason I won't use Dexcool......

Back when GM began to use Dexcool in LT1s back in the mid 90s, FBody & Impala SS owners started to notice that our heaters wouldn't work.

Turns out the "stuff" in Dexcool was clogging up the heater cores. The fix was to disconnect the heater hoses from the engine and flush the heater core out with water using a garden hose.

I did this to my 96 Impala SS in the winter of 97 and can tell you that the Orange/Brown muddy goo that came out was enough for me to flush the entire cooling system on that LT1 and refill with the good ole' green stuff.

The TSB for this fix stated that the cause was a lack of use of the heaters during the summer which led to the buildup of the Dexcool goo in the core and heater hoses.

With that in mind, I would hate to think of what Dexcool muddy goo might be doing to a LT5 that is only a sunny day driver.

JMHO-YMMV...... ;)

[TommyL]

Oh boy, this is great. An actual dealer that will corroborate the story of head gasket failure due to or “connected with” Dexcool. Can I get the name of the dealer? I won’t mention where I heard it just confirm the issue with the 4.6 V6. The dealer is in Ontario?
I just want to nail this down so that I might convert back to the green stuff. Or if the issue is still related to the nylon/Silicone type gaskets then I will report on that.

Brian Finch Pontiac Buick GMC Ltd. 1-888-257-4354

Give them a call!

[TFENT]

I had this same issue with my 96 Impala SS. There were rumors of GM using some kind of clay tabs but I flushed the system and installed a 75/25 combination of Distilled water (75%) Amsoil antifreeze (25%) with 2 bottles of water wetter and a bottle of RMI-25. Zero issues to date since. I also run this combination in all my vehicles.

http://i84.photobucket.com/albums/k26/ssmokybear/Impala%20SS/DSCN1095.jpg



http://i84.photobucket.com/albums/k26/ssmokybear/Impala%20SS/DSCN1102.jpg

http://i84.photobucket.com/albums/k26/ssmokybear/Impala%20SS/ISSCA_AutoCross_Race_A_067.jpg

[scottfab]

Yup, heard about the brown messy stuff too. That is a well known issue. I think the reason posted was contamination (bacteria?) but again, I have never seen it in mine.
Maybe cause I flushed it well enough on conversion or maybe because I used distilled water or maybe because I am lucky? Who knows.
Central issue (for me) is the gasket errosion being blamed on Dexcool.
If I can nail that one down it would be great.

[LT5-Lee]

I have been reading along and figured I might offer one piece of info to really complicate things further?:confused:

I also have been using DEX-COOL in my Z for 8 years or so, but it has only seen around 13,000 miles and I also installed one of those Rad Caps, with the hanging zinc anode, which is gone now so I figure it worked, but I have not been able to find another RAD CAP replacement as they seem discontinued? I did notice some brown gunk in the overflow tank.

I figured I would just fab another anode on the chain, but now I also want to flush the system so I hope you guys figure out the BEST possible. I know I would squeeze the "jolly juice" out of a gofer if it would keep me from a HG problem!

[TFENT]

I highly recommend using the RMI-25 to initially flush the system then add another bottle after the flush to keep the system clean. My Overflow bottles are spotless after years and years of either storage or running.

[LT5-Lee]

I highly recommend using the RMI-25 to initially flush the system then add another bottle after the flush to keep the system clean. My Overflow bottles are spotless after years and years of either storage or running.

RMI-25..? HUmmm, I never heard of it. You might have made one gofer very happy!:)

[TFENT]

RMI-25..? HUmmm, I never heard of it. You might have made one gofer very happy!:)

Here is a link where i get it from. There is a short video showing it working. ;) http://www.technilube.com/rmi25/index.php

[Aurora40]

Is Prestone Extended Life antifreeze a good selection for the LT5 engine?
In short, no.

Prestone's Extended Life, or "All Makes" coolant is basically a version of Dex-Cool. It is an OAT coolant vs a silicated coolant that was originally spec'd for the LT5.

I could be wrong but I don't believe Prestone makes any silicated EG coolant. The only thing I'd consider is their Low-Tox coolant. It is a silicated coolant like the LT5 came with, but it is made from propylene glycol vs EG. That's what makes it low tox. GM has released TSB's saying PG coolants are fine for use in their cars, but of course they have never done any real certification testing with it.

I run low-tox coolant in my LT5 now. Partly because I can't find any EG silicated coolant, and low-tox I can get locally. Also partly because the car drips coolant sometimes, or at least it has in the past, and I am not a fan of dripping toxins.

[Hammer]

Thanks :thumbsup:......I see this discussion has been going on for 2-1/2 years with mixed results. Just tell me a brand of coolant I should use and if I can get it at WalMart, Autozone, Kragens :D

I've kept an eye out at the stores you mentioned and have not found a coolant that meets the 1825M requirement in the brands they carry. The only place I have found the 1825M coolant for our cars is NAPA. Their house brand coolant has the silicates and the 1825M rating. $8.99 a gallon. I have used it in both cars now with no problems with #458 having around 20k miles on it.

[ZR1Vette]

Based on recommendations of several 'LT5 gurus' and Texaco I went with Texaco Anti-Freeze Coolant (aka 'Green Stuff')... it is GM 1825M certified>>>

https://www.cbest.chevron.com/generated/MSDS/PDS7641156.PDF

Just my choice...

[Hammer]

I will check NAPA today (between WalMart and Kragens :))....thanks Hammer :thumbsup:

And thank you for those nice avatars :thumbsup:

You're welcome, looks like yours aren't bad either.

[USAFPILOT]

I just had Jiffy Lube flush out the orange dexcool and fill it with their 50/50 green that they use for most all other cars. I thought until after reading this that the green was good and orange dexcool was bad. Anyone got an idea of what exactly I had them put it? I guess I could go ask. I know it isn't dexcool, but I dont know if it is silicated or whatever? At least something fresh is in there for now. We had to run like 40 quarts through it before all the orange stuff was out as well. It took quite a while. Again, all I asked them for was 50/50 regular green antifreeze. But it didn't really look all that green. It was watered down alot. More of a yellowish tint.

[ZR1Vette]

More of a yellowish tint.

That sounds like they put in a product such as Prestone Extended Life which is not GM 1825M approved, but rather GM 6277M spec which makes it DEX COOL compatible (and this is not what the LT5 uses). I go back to Jiffy Lube and ask what they use and if it is what I suggested then you need to replace.

[Aurora40]

As mentioned, NAPA may have silicated coolant. Michael, where do you buy the Texaco stuff? Texaco formulated the Dex-Cool for GM, and has been the maker of other fluids as well (I want to say the original ZF fluid was Texaco oil). I'd trust their brand.

But GM still sells the green silicated stuff. If you want to be 100% positive, this would be the no-risk way to go. And it's available anywhere a GM dealer is. But you will pay for it for sure. I think the last time I bought a gallon it was close to $30 from GM.

Dynomite, I'm not sure there are diverse opinions on anti-freeze? Maybe I have to re-read the thread again, but I believe most everyone feels the originally spec'd coolant is the best way to go.

[Scrrem]

Ok, now that I have a water pump to replace, I have read this entire thread (Whew!!!) and am watching with great interest. It seems like Texaco is the way to go, now the hunt to find some.
Rich

[ZR1Vette]

There are a few remaining Texaco stations in Northern Va... I got the green stuff at a Texaco station in Falls Church area. Since Texaco is now Cheveron/Texaco, Cheveron stations sell a antifreeze which appears to be the Texaco green stuff, but relabeled... now to the "appears" part...I have not confirmed as fact.

[SharkPilot]

I have read through this thread and I'm still not sure about what is safe and what isn't. Okay, I know that Dexcool is a bad idea. So perhaps you guys can take a look at what I'm using and give me some opinions...

Right now I have Peak Long Life 50/50 Prediluted in the cooling system of my '91. The ingredients are: Water (7732-18-5), Ethylene Glycol (107-21-1), Diethylene Glycol (111-46-6), NJTSRN QT1.

Lower down on the label it states: "Meets ASTM D-3306 and ASTM D-4340"

So what does all this mean? The numbers following the ingredients are a mystery to me. What is the "NJTSRN QT1"?
I got this stuff at AutoZone but have also seen it at NAPA stores around here too.

So fire away and let me know what you think.

Thanks, SharkPilot

[ZR1Vette]

First, Peak Long Life lists several ingredients, including the NJTSRN QT1 which tech jargon for their "proprietary mystery" ingredient(s) that the manufacturer doesn't want to share with us as to the specifics. It is the same ingredients found in DexCool, which is under fire for engine damage (here is an example of one of many litigation's concerning this issue>> http://www.dexcoolsettlement.com/notice.pdf ).

Peak Long Life is listed as being compliant to GM 1825M (which is a performance standard not a chemical composition guideline), but at the same time does note "Contains no phosphates or silicates"

ASTM D-3306
This specification covers the requirements for ethylene glycol or propylene glycol base engine coolants used in automobiles or other light duty service cooling systems. When concentrates are used at 40 to 70 % concentration by volume in water, or when prediluted glycol base engine coolants (50 volume % minimum) are used without further dilution, they will function effectively to provide protection against freezing, boiling, and corrosion.

ASTM D-4340
This test method provides a means for selectively screening unused engine coolants and will readily distinguish those coolants that are unsuitable for use with aluminum cylinder head engines. However, satisfactory performance of a coolant in this test method does not ensure adequate long-term service performance.

[QB93Z]

Thanks Michael.

Jim

[tomtom72]

I know that I took the easy, but expensive, way out with my car. I buy the GM stuff over the internet. Only draw back is the dealer I used to use is no longer a chevy dealer. Most of the local chevy stores near me don't stock the stuff and are not too keen on ordering one case for an over the counter customer.

The GM part number for the stuff that came in our cars is: 12378560....well that was the P/N two yrs ago.

:cheers:
Tom

[Scrrem]

I know that I took the easy, but expensive, way out with my car. I buy the GM stuff over the internet. Only draw back is the dealer I used to use is no longer a chevy dealer. Most of the local chevy stores near me don't stock the stuff and are not too keen on ordering one case for an over the counter customer.

The GM part number for the stuff that came in our cars is: 12378560....well that was the P/N two yrs ago.

:cheers:
Tom

You can order here: http://gmpartsdirect.com/

Rich

[QB93Z]

My experience is that when I spend time running around town doing all the searching and find the coolant I plan to use. I record all the info off the container and the store where I bought it.

4 months later I go back to that store and they don't carry that stuff any more. So I have to do all the running around and research all over again.:icon_scra

I think the manufacturers purposely keep switching the labels and mixtures so that they can't ever get pinned down on exactly what they are selling.:dontknow:

Rant over, thanks for listening.

Jim

[PhillipsLT5]

Try Zerex, original formula, 1825M on label, from NAPA

[95ZR1#418]

Hi All-

Well, after reading this thread I started to freak out because I just went through my coolant system(stat,hoses,flush) and had no intention to put DexiCool in it. Then I see Prestone "Extended Life" is the same as Dexicool. I used Prestone to refill my system, 10% with distilled water and water wetter.

So out to the garage I go to read my Prestone bottle.

The front of the yellow 1 gal. jug says: NEW Formula! ALL Makes, ALL Models. Mix with any color antifreeze. Extended Life Antifreeze/Coolant(caps were as I printed here).

The Back of jug says:
Warning: Contains Ethylene glycol(107-21-1), Diethylene glycol(111-46-6), Sodium 2-ethyl hexanoate(19766-89-3), and Sodium neodecanoate(31548-27-3).

From what I read here, this containing Ethylene glycol, this prestone product should be O.K. to use, meaning it is not Dexicool, is this correct logic??


The product goes on to state: Intended for all passenger vehicles & light trucks. Compatible with ANY make or model on the road today. Designed to provide up to 5 years or 150,000 miles of protection for extended performance when added to ANY EXTENDED LIFE antifreeze/coolant(The caps were in the write up). Protects aluminum & all other engine metals. The product does not specifically state it meets GM 1825M spec

Tell me this is O.K., and is not the extended life others have mentioned here. I bought this Prestone in March of 2006.....:confused:

[95ZR1#418]

Originally Posted by Dynomite http://www.zr1netregistry.com/forum/images/buttons/viewpost.gif (http://www.zr1netregistry.com/forum/showthread.php?p=76973#post76973)
Is Prestone Extended Life antifreeze a good selection for the LT5 engine?



I asked Z Factor to set up a "what antifreeze do you use" survey similar to the "what oil do you use" survey. That would be very interesting for a lot of us :D

...But this doesn't make any sense(see my post above). The Prestone extended life I'm using lists Ethylene glycol as the basic ingredient. As others have stated, this is what you want, an ethylene glycol based coolant, "the old stuff". So how can it be considered the same as Dexicool???:confused:

[ZR1Vette]

The LT5 requires silicates... Prestone Extended Life info states:

Prestone® Extended Life 5/150 Antifreeze/Coolant (http://www.prestone.com/products/antifreezeCoolant.php#extendedLife) is phosphate, silicate, and borate free. This coolant uses a special chemistry and technology (basically HOAT/OAT) that extends the life of the corrosion inhibitor package so that it lasts for five years or 150,000 miles (whichever comes first), and is safe for all cars and light trucks. Prestone® Extended Life 5/150 Antifreeze/Coolant (http://www.prestone.com/products/antifreezeCoolant.php#extendedLife) has been approved by General Motors under their DEX-COOL® specifications and is compatible with other DEX-COOL® approved coolants.

Also, OAT (Organic Acid Technology) & HOAT (Hybrid Organic Acid Technology) based antifreezes should not be used with the LT5 engine so you need to take a peak at this chart>>
http://www.eetcorp.com/antifreeze/Coolants_matrix.pdf

As a 'rule of thumb'>>>
Even though raw coolant has no color, manufacturers dye the coolant to help discern different types of coolant. Most cars manufactured before 1995 were designed to run the traditional "green stuff," which contain silicates that coat and protect cooling system components. However, these silicates deplete more quickly, requiring coolant changes every two years or 24,000 miles. Bascially, post 1995 GM cars use Dex Cool and can not use silicated (aka Green Stuff) coolant and vice versa pre 1995 can not and should not use Dex Cool (or non silicated/OAT/HOAT) coolants.

I am not a coolant engineer or chemist, but base my comments on research and talking to those who understand coolant chemistry and automotive applications. I DO agree that this subject is difficult due to manufacturers vague information on formulation and attempts the 'one size fits all aka "safe for all cars and light trucks" which is blantly not true. Called marketing driving "facts" for market share.

[Hammer]

The NAPA brand antifreeze is the only antifreeze I have found in the common stores that meets all the requirements of the 1825M GM designation. I did not look at the Zerex, so that might be OK too. The NAPA brand has the silicates needed shown in the ingrediants.

[tomtom72]

You can order here: http://gmpartsdirect.com/

Rich

Thank you Rich. I rarely use those guys as they make up their margin on the shipping charges. I was a solid customer of P & G Chevy in PA. They lost the GM franchise upon the re-organization shuffle.

It was nice at P & G as I was on a first name basis with the parts dept. there!:redface:

Guess I'll check out the local NAPA store & see what they have on hand. I always felt that using the GM stuff eliminated any guess work on my part and that it was the safe, albeit, costlier purchase.

:cheers:
Tom

[Aurora40]

From what I read here, this containing Ethylene glycol, this prestone product should be O.K. to use, meaning it is not Dexicool, is this correct logic??
No, that is incorrect logic. Dex-Cool is an ethylene glycol based coolant. All automotive coolants except "low tox" coolants are ethylene glycol. The EG is what modifies the boiling and freezing point of the water you add it to. And it makes the coolant "slick" to lubricate the pump. But the protection package is what makes the difference.

Dex-cool uses organic acid technology as a protectant. Older coolants use silicates and phosphates. There are also others, like the mentioned Zerex which is a hybrid organic acid technology. It is sort of a combination of Dex-Cool and the old stuff, though obviously it's more complex than that.

[Aurora40]

The product goes on to state: Intended for all passenger vehicles & light trucks. Compatible with ANY make or model on the road today. Designed to provide up to 5 years or 150,000 miles of protection for extended performance when added to ANY EXTENDED LIFE antifreeze/coolant(The caps were in the write up). Protects aluminum & all other engine metals. The product does not specifically state it meets GM 1825M spec
Just FYI, though it is irrelevant for our cars since you shouldn't do it in the first place...

But that last bit is true of any OAT product. If you drain out silicated coolant and then fill with Dex-Cool or similar, you will not get the long-life protection offered by the OAT coolant. Apparently the silicates coating everything can prevent the OAT stuff from doing their job properly. The Dex-Cool will still be safe (assuming the car can use Dex-Cool), but you'll want to change it at normal intervals, i.e. every two years.

[95ZR1#418]

Guess I'm going to flush mine now.
I contacted GMPARTSDIRECT with the PN: 12378560 to be sure this was correct, then ordered a gallon promising never to sell it to any ZR-1 owners in Oregon(I totally agree, those people can't be trusted with anything).

GMPARTS reply:
Hi Bob,
I am providing the information we have for part number 12378560.

PRODUCT DESCRIPTION AND FUNCTION:
A high-boiling, non-evaporating antifreeze-coolant preparation
containing chemical ingredients to protect against rust and
corrosion. Can be used with either low- or high-opening
thermostats and at high altitudes. It will not harm rubber
hoses, pump seals, or gaskets.
GM Antifreeze-Coolant mixes perfectly with water, flows freely
and transfers heat efficiently. Protects to -34¡F. Protects
aluminum components.

GM VEHICLE APPLICATION:
For 1995 and prior vehicles except medium-duty truck.

SPECIAL PRECAUTION:
Do not add to cooling systems that require DEX-COOL.
In compliance with the Oregon Toxic Household Act, Antifreeze
Products can only be purchased for use in professional vehicle
repair facilities and cannot be displayed for sale or sold to con-
sumers. By ordering this product, you agree not to sell it to cus-
tomers in Oregon.


Thanks Floyd,
GmpartsDirect.com (http://gmpartsdirect.com/)
When replying to emails please include all previous email correspondences so we can better assist you.

[bdw18_123]

I didn't know that the antifreeze thing was as complicated as the oil issue for our cars. It sucks having to wade through all the BS that the manufacturers throw at you just to figure out the proper stuff to put in. After reading through this thread and the equally long oil thread, this is what I'm going to use for antifreeze and oil when I get my Z back together:

Antifreeze: Going to check Napa for the 1825-M stuff (I think Hammer said it was the house brand?) & will use that if they have it. The Napa store near me is also a Napa warehouse, so they probably have some stuff that the normal small Napa's don't have.

I have never used the "water-wetter" stuff before, is it something that is absolutely necessary? What is it supposed to do? The less crap I have to buy the better...

Oil: From what I read in the oil thread, the Mobil 1 fully synthetic high mileage stuff has some extra Zinc compared to the regular fully synth stuff & I can get it from my local store. I know it's not quite the same amount of zinc as is recommended, but I think it's close enough to not be an issue.



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[95ZR1#418]

I have never used the "water-wetter" stuff before, is it something that is absolutely necessary?


Mobil 1 fully synthetic high mileage.

You don't need the "water wetter" by any means; you can find the same lengthy threads about its benefits. If not the NAPA brand then do what I just did, get the GM stuff, and use distilled water (50/50).

I also use the Mobil 1 synthetic high mileage.

[Aurora40]

then ordered a gallon
FYI, the system holds about 3 gallons total. So you will need to get two gallon containers of anti-freeze to mix up >3 gallons of 50/50.

[95ZR1#418]

FYI, the system holds about 3 gallons total. So you will need to get two gallon containers of anti-freeze to mix up >3 gallons of 50/50.

I mentioned 50/50 because that's what most people use, personally, I use 10% as mentioned in an earlier post.

[bdw18_123]

After starting this thread back up three days ago I have come to the same conclusions :thumbsup:

Lucky for me my engine is in parts for a while and I can think some more on these antifreeze and oil issues :thumbsup:

My LT5 is in the same state, in pieces all over the garage (and some in the house)! :mrgreen:

[PhillipsLT5]

Yes, original formula as pictured shows 1825M, yes correct oil as per Marc H(Zinc on label)