RE: Replacing coolant...

[Paul Workman]

Originally Posted by jonszr1

napa has 1825 spec its alot less than gm works fine

Good to know. Thanks for that.

Having said that, inquiring minds would like to know...Is the silicate additive really all that important, chemically speaking, or have other lubricants/corrosion inhibitors now used in the "green" (ethylene glycol+) solutions taken their place (successfully)???

Unlike most of today's oils that do not have the proper amount of phosphorus, zinc, etc which does have an impact on our LT5s, as far as cooling goes, aluminum then is aluminum now. So, forgive my ignorance, but I have to question whether pump bearings and seals really give a ratz azz what the lube is in the antifreeze. (I'll continue using the silicate stuff in the mean time, but some data that would stand up to scientific process would be nice to see, if someone has it. )

P.

[tomtom72]

As I understand the situation our head gaskets do not tolerate coolants like DEXCOOL. Something in it attacks the gasket material and causes the gasket to delaminate, swell and leak. I do believe that the formulation is an organic acid based on most coolants in the DEXCOOL generation of coolants.

The 1825-M generation was some different formulation chemically vs the DEXCOOL generation of coolants. I think the 1825-M stuff is salt based vs. the newer organic acid based coolants.......I think..

[Paul Workman]

Originally Posted by tomtom72

As I understand the situation our head gaskets do not tolerate coolants like DEXCOOL. Something in it attacks the gasket material and causes the gasket to delaminate, swell and leak. I do believe that the formulation is an organic acid based on most coolants in the DEXCOOL generation of coolants.

The 1825-M generation was some different formulation chemically vs the DEXCOOL generation of coolants. I think the 1825-M stuff is salt based vs. the newer organic acid based coolants.......I think..

Well, enough has been said about the issues w/ Dexcool that I wouldn't go near it - now or ever. As far as salts go, according to the label on my "green stuff", there are two glycol solutions, but also two sodium (Na) compounds listed as well..possibly be the salts you mentioned (but my chemistry learnin' was never that good anyway ).

BTW, I got the "green stuff" from Napa (I checked) and not from Federated as I thought (earlier).

P.

[jonszr1]

paul you might do a thread search ,this was discussed atsome length a while back . the issue is the head gaskets . its not too tough to change head gaskets you just have to pull the engine and buy 400 dollars worth of tools etc to set the cam timming. which is really scary the first time you do it. its one of those jobs that youdont want to do if you can help it Jmho

[32valvZ]

Originally Posted by Paul Workman

Well, enough has been said about the issues w/ Dexcool that I wouldn't go near it - now or ever. As far as salts go, according to the label on my "green stuff", there are two glycol solutions, but also two sodium (Na) compounds listed as well..possibly be the salts you mentioned (but my chemistry learnin' was never that good anyway ).

BTW, I got the "green stuff" from Napa (I checked) and not from Federated as I thought (earlier).

P.

I used the stuff from NAPA also. Its Zerex.

[White Bullet]

Sounds like any green coolant that meets the GM spec is acceptable. There are plenty of NAPA stores around here so getting it will be simple enough. Now for the fun part, installing the parts. Thanks.

[Aurora40]

Originally Posted by Paul Workman

Having said that, inquiring minds would like to know...Is the silicate additive really all that important, chemically speaking, or have other lubricants/corrosion inhibitors now used in the "green" (ethylene glycol+) solutions taken their place (successfully)???

There are newer ones that successfully take their place. They are generally OATs (organic acid technologies) or hybrid OATs (usually a mix of OAT and silicates). The problem is that OATs are what is in DexCool. They work great on engines designed for it, not so great on engines that were not.

I'm not aware of anything else that doesn't have either silicates or some form of OAT.

Much like motor oil, though (and ZF6 lube), I suspect most of us would be happy to use what was originally spec'd for the motor. The problem is you can't get it anymore, so that's when you have to make sure the stuff you are using contains what your old motor still needs. If you make the same argument for coolant, well the thing is is you can still get the original spec stuff. So why not? It works fine and won't cause problems, so why take a chance? When silicated coolants disappear, then maybe we'll have to do some researching...

[White Bullet]

FYI, Napa has the right coolant. Meets the GM spec and has silicate’s in the mix. $10.99 a gallon.

[Z51JEFF]

I would like to flush the system,I have no idea whats in there.Would it be possible to run distilled water through the system to clean it and then slowly drain off the distilled water,siphon some off and then top it off with correct coolent?When I did the injectors a few months back there was a bit of corrosion in the system.Is it possible to completely eliminate the corrosion in these engines?

[tomtom72]

Jeff, what kind of corrosion? Flakes & scale...kind of white to ashen looking stuff? Most of the time that is the results of "galvanic Action" = two or more dis-similar metals in water. The condition makes a battery. The current causes the salts in the coolant to percipitate out of soloution, scale. You can look up "Electrolytic Corrosion" also, same thing. Make sure all the grounds on the motor are clean, tight & have liberal di-electric grease coatings....I might add that all the connectors in the harness could use the same grease.

Using steam distilled water in the cooling system will mitigate the galvanic action, no salts like tap water. Flushing using plain tap water repeatedly and then drain and then use distilled for a few flushes after the drained tap water comes clear should work for most normally contaminated ZR-1's. Then just fill with 1825-M spec coolant to 50/50 mix & make sure every two yrs at the most you repeat. The FSM says not to use any of the caustic flushes sold at the parts stores. If the flakes are really bad you can take out the T-stat and reassemble the housing so it leaks fairly well. Stick a hose in the upper fill tank and then idle the motor till the run-off comes clear. I doubt that your system is really scalled up as most people heed the warnings in our owner's manual about the two yr interval. The issue is that they use tap water every two yrs and you get the small amount of scale build up. Try just flushing and see what happens.


Tom