I find it hard to believe that aluminum cans can hold carbonic acid and phosphoric acid for years, but the dissolved calcium in 2 gallons of tap water dissentegrated a radiator in 6 months.

I do believe the radiator failed, I just believe there is alot more to the story.

 

Back in the mid 90's we knew that Dexcool was bad for plastic/RTV gaskets. Designers didn't realize how much the RTV/silicone beads would expand/swell when in contact with Dexcool. This would swell and break the plastic carrier (body) of the gaskets..big leaks! Those with chevy trucks know what I'm saying. Skip ahead 10 years and now it's a big issue with most engines now with plastic intakes or plastic intake gaskets. FP came up with a MLS metal gasket, unfortunately marketing messed up an add and they got their pp's whacked! Never mention that this is a "warranty fix" when GM denies there's a problem...can you say big lawsuit!!

Around this same time (90's) G-05 was new, came in several colors but that was just for different car manufactures...straight from coolant engineer we worked with. We would get 55 Gal drums 50/50 mix with distilled water for testing and I was using in my '97 PT GP-GT. He explained the simple difference between Green, OAT, HOAT coolants and the push the EPA was putting O.E.'s to cut back on phosphates, which is a natural corrosion inhibitor. This is also happening more and more with oil as you may have read here on the forum. Most recommend diesel oils which still have the better additive packages compared to "regular oils" which have ever changing API ratings.

Simply, Green with it's (higher phosphates-etc) rust inhibitor packages was in need of "replacement" to cut back on the amount produced. Think about the amount of cars on the road and the volume of coolant produced, cut back on the need to change it and you cut back on what needs to be produced annually and it's affect on the envionment. Kind of win-win. So out comes longer life OAT, Organic Acid Technology, had "zero" phosphates, so no more natural rust inhibitor coating all those cast iron surfaces = rusty gel or goo we've all seen. Next came HOAT, Hybrid Organ Acid Technology, which is a better blend of an inhibitor package to help with cast iron blocks and no gel, but yet long life.

Now, my metallurgist ex-coworker used to laugh when he heard people switching coolant types "mid-stream". He always talked about cathode /anode issues with bi-metal engines and coolant types. I never saw issues with mixing test engines and cooling towers (dyno stands) that used either coolant, but we would simply rinse and reuse parts all the time. Never mixed the different types, or cross streams either.

Did a lot of testing with G-05, will use it in my '70 with aluminum rad, water pump and cast iron block with no issues (if I ever get it going). But then again, I'm starting with all new upgraded gaskets and hardware compared to those with their "oringinal" cars so it will be fine.

Hope this helps a little, not ment to be a science class, just a little history and background to why things had to change.

 

Very informative

 

Good stuff. Answers many questions.

 

There might be more to it but as a manufacturer when something goes wrong you have to ask yourself, did we do this? Was this a defect in the material or workmenship, as our warranty states? The answer is no, it wasn't. Short of having this sent to a lab to determine the actual make up of the white crusty stuff, I can only guess at exactly what it is. It could be calcium deposits or it could be somekind of electrolysis or some other mineral, but all I need to know is "did we do it" to determine warranty. We don't get too many of these warranty cases, but we never had one when the owner was using distilled water and in every case the inside of the radiator is coated in red rust which is an indication of high iron content and a poor inhibitor package.

 

Great stuff Gasket Dude.

 

Tons of information in this post but I have to say, I am getting majorly confused on what is the best thing for my baby. I have Dexcool in there now and had planned on putting new Dexcool in shortly as I am changing hoses. Now some folks say Dexcool is ok and problems fixed, some say there are no problems if used properly, others say.....

I am going to go home and drink until it all becomes clear

 

Well lets just break this down. Dex's advantage is a five year life over green's one year life and the new Prestone's yellow with a two year life.

Time or frequency of when you change should be the deciding factor. If you flush every year or two anyway then green or yellow is your choice. If you can't seem to flush more than once every five years...then use Dex. Just DON'T mix the two.

 

Flush your system properly.
Pick any antifreeze and mix only distilled water with it; or use the premixed.

It doesn't matter what type you use if you drain and replace once a year. Well worth the 20 bucks it costs.

Sit back and drink some more knowing it's OK

 

Thanks. I really do need it in, "...so simple a caveman could do it" terms.

 

It's no big deal...it's really just a simple decision. Either way, a flush and fill is in your future...you just need to decide which one you want.

 

Thanks to Tom DeWitt for his knowledge and experience. I will remember that come radiator time.

As you fellows get older, you will come to appreciate a clean-flowing system and regular flushing.........

It's threads like this one that make me really appreciate the forum.

 

I use the green only and I seem to wind up changing it annually without even necessarily meaining to. Last year it was to replace all the hoses, this year everything is apart for engine detailing and painting.