If you are arguing, you are in a room by yourself.

I have shown proof your statement that Dex-Cool and yellow Prestone is incorrect. You are not proving your case. Instead of blowing hot air around. Get some facts together and present your case. Stop posting BS.

EDIT: Chart showing all manufactures makes. Heavy Duty Prestone is not a MOA antifreeze.
http://www.eetcorp.com/antifreeze/Coolants_matrix.pdf

 

You haven't shown prove of anything other that your own inabilty to comprehend simple facts.

One more time ~ Prestone Any Make/Model is a Dex-Cool Clone

This will be my last response to the uninformed in this thread.

 

 

I just wanted to drop a comment here:

I have to agree with Mako41 when he says*:

Regardless of the similarities or disimilarities between the two Prestone coolants, NEITHER is the OEM coolant for any GM vehicle produced before the advent of Organic Acid Technology and Dex-Cool® in 1995. It was upsetting to discover the local GM dealership replaced my TRUE old North-American green coolant with Dex-Cool in my 1991 corvette 2 years ago.

If the OP is asking which coolant was OEM for his 1996 corvette, it is Dex-Cool. Problem solved.

Now if Dex-Cool is a good coolant for pre- and post-OAT GM vehicles is an entirely different discussion. I did not want it in my 1991 GM and suffered the consequences of dealership service. I am now more mechanically-inclined and used Napa Antifreeze/Coolant in my recent coolant/intake gasket/thermostat/water pump change. I am not solely basing its composition on color; the NAPA brand coolant is one of the few true silicate and phosphate formulated ethylene glycol coolants. My vehicle will never see Dex-Cool again while in my possession.


Suitable replacement for GM Vehicles manufactured before 1995:



‘Old-School’ Silicate and Phosphate corrosion-inhibition technology:



Good luck to the OP,

Jonathan

*Edited for spelling and grammar.

 

Yes that NAPA house brand is a true old school silicate and phosphate corrosion package type coolant. I believe it is made by Peak for NAPA and can be used for all pre '95 GM spec'd vehicles.

Change it often and it will work fine for your '91 vette. It's not modern day technology as far as coolant goes but it does work OK.

Ryan59 this is a coolant that closely resembles what you thought Prestone Any Make/Model is, but is not!

The reason OAT and HOAT type coolants were developed was the corrosion protection over time with the those old style hi-silicate formulas was lacking. The newer OAT type coolant contains no silicates for corrosion protection. They use a different technology, while the Hybrid OAT or HOAT type coolants contain some silicates in them but not enough to fall out of solution and cause cooling system sludge problems.

 

Yep, that is correct. It is suitable for pre- 1995 GM vehicles and is produced by the same company that manufactures Peak brand fluids.

Again, .


Uhuh, but I have used properly maintained Dex-Cool and experienced some of the aforementioned issues. The coolant became thick and upon removal of the knock sensor and block plug, it was evident that more clotting was present than I anticipated. Additionally, Dex-Cool may or may not have contributed to my overheating issue. Instead, I'll take my chances with the 'old' style coolant and continue fluid changes at set time intervals.

-Jonathan

 

The reason you and many others have had sludge problems with Dex-Cool is that is doesn't work very well in open-air or nonpressurized coolant recovery (overflow) bottles. Do you store your vette for the winter?? This isn't good for Dex-Cool filled vehicles. Our C4's are prone to air pockets in the cooling system that cannot be seen and lead to the sludge you experienced.

I have recommended GO5 or HOAT type coolant for our C4's (I have an '89) because it has all the advantages of newer coolant technology, with increased corrosion protection and longer life, with non of the (Dex-Cool) nightmares.

 

I live in Florida - it is driven year-round. I will definitely look into the GO5 technology more.

-Jonathan

 

Despite the bickering, this has been a rather informative discussion thread - thanks for all the great info mako41.

I know I used the Prestone Dex-Cool clone yellow green colored product during the last coolant change (I change the coolant in my car once a year). Obviously I didn't know that it was a Dex-Cool clone, otherwise I never would have used it. My car is stored for the winter now, and I've drained the coolant from the system (which I do every winter), but based on this discussion when I put the car back on the road in the spring I won't be using Prestone.

With that said, I am curious if the AC Delco brand coolant (not Dex-Cool, but the green stuff in the white bottle with the blue and red label you get from the GM parts counter) is the same as the Prestone Dex-Cool clone? I used to use AC Delco brand coolant up until about two years ago; I only switched to the Prestone because of availability (GM parts counters close up shop rather early in my neck of the woods). Any idea if the "regular" AC Delco coolant is a Dex-Cool clone?

I can't say as I've ever experienced a problem with ether the AC Delco or the Prestone products, but given this new information I know not to tempt fate in the future.

 

I'm sure you know AC-Delco does not make and bottle their own coolant. Try to determine who makes the coolant they sell. Do you have a jug, read the label! Who makes it? Is it made by Prestone, that would probably mean it's a Dex-Cool clone but it may not be.

It may be made by Peak or possible Zerex, and be an old GM spec silicate-phosphate corrosion protection type coolant. Read the ingredients on the jug label and compare them to the jug label pics posted in this thread, that should answer your question.

I don't think it's a good idea to drain the coolant out of your vette every winter. Air pockets in your cooling system during storage will lead to corrosion reguardless of what type coolant you use! It would be a better idea to fill the cooling system with fresh coolant and burp and pack the system until all the air is out then store the vette for the winter.

 

 

I believe PEAK is the only company still to sell the original Green antifreeze.

the "mix with any color" stuff, seems to be yellowish.

I can't see there being much of a market for green antifreeze anymore.

The peak web site is pretty good.
I havn't checked out the prestone site yet.

I personally have ran dexcool for 9 years no problems... until the plastic radiator tanks crack..... but that would have happened regardless.

 

Normally I would have checked the jug to read up on the ingredients or to try and determine who the manufacturer might be before asking the question. Unfortunately I'm not in my home country right now and won't be for another week and a half. And, I'm not certain that I still have any (spent) jugs left in the garage. But if I do, I will check as soon as I get home. I just thought I'd ask in the event that you knew off the top of your head - as you seem well versed on the subject of coolants.

And yes, I am aware that AC Delco doesn't make their own coolant. In fact, I'd be surprised if they genuinely make even 50% of the products they sell. But that's a topic for another discussion.

I used to store my Corvette with coolant, but I stopped doing that based on an article I had read (I can't remember the source) about storing a car. The writer's claim was that coolant was the second most corrosive material in the vehicle behind brake fluid, and by draining it, it would minimize the potential damage it could cause to gaskets (particularly head and intake gaskets).

Now that I think about it, there was no mention of draining the most corrosive material, brake fluid, for winter storage. Makes me wonder whether the writer really knew what he was talking about...

But either way, if the general consensus is to store a car with coolant, then I don't have an issue with doing so. It just means less work for me when storing my car.

 

New radiator, water pump, distributor, hoses. I decided to go with Sierra propylene glycol coolant for the less toxic choice. Proplyene glycol is commonly used as a dough conditioner etc., and is non toxic to humans and pets. Ethylene glycol is very toxic, one tablespoon is deadly. Sierra has all of the standard corrosion resistant specifications.
We'll see in a few years.

ps
Replaced my old Ron Davis radiator with a new Rod Davis radiator.
The new one fits much better, being 1" shorter.

Any hints on getting air out of the cooling system?

 

Try drilling a 1/8" hole in the thermostat flange. Point it towards the front of the car. Search the forum archives for "burping" the engine after a coolant change. Pockets of air in these engines can be very harmful.

 

I believe Corvette Kid is right on. I have spent all of my career (Elastomer/polymer chemist) looking at the effects of various automotive fluids on elastomers and depending on the type and level of corrosion inhibitors formulated into the coolant (even very small amounts) can have serious degrading effect on seals, gaskets and hoses. Elastomer types have been upgraded thru the years to keep up with the changing fluids. Be careful and follow dealer guidelines.

 

If you mean right on about draining the coolant for winter storage I would have to strongly disagree. Reguardless of the real or imagined degrading effects any coolant may or may not have on seals, gaskets, or hoses the internal corrosion that would occur inside your engine block, heads and radiator would certainly outweigh the thought of trying to save those seals and gaskets by draining your coolant for winter storage. Seals gaskets, and hoses can be more easily replaced than your entire block or heads, or even the radiator!

 

Anyone running G-05 in your 95 or newer Vette?

 

This is what goes in my 95.

 

I'm running GO5 or HOAT in my '89. I am using the Mopar version dyed bright orange. Looks like Dex-Cool.