Bill Jennings

I just bought a DeWitt all aluminum radiator for my 95 LT1. Their instructions say that for extended life to use Prestone, Zerex G-05, or Peak (green) antifreeze. I thought that only Dex-Cool antifreeze was supposed to be used in this engine. Can anybody advise the correct antifreeze to use on an LT1 with 95k miles?

Richard Raichert

From what my manual and what I have been told, "green" antifreeze is to be used in our engines and not Dex-Cool as it will harm our aluminum engines. See what others chime in on this.

crowz

Ive run green in my lt1 firebird for 280k miles. Works great.

enventr

My 95 came with orange ( prob dexcool) when I bought it over 8 years ago . I flushed it all out and have been using 50/50 premixed prestone (green color) especially in my Dewitt's radiator. I don't remember where I have read it but mid year 95 they switched to dexcool and are using it in the 96 from factory. I know others will chime in

c4cruiser

Use the coolant specified in the '95 Owner's Manual. If it says to use an extended-life coolant, Dex-Cool (Or any other coolant that is labeled as a long-life coolant) will work fine. Prestone Dex-cool is available as a concentrated coolant or a 50-50 pre-mix. For a complete flush/fill, get 2 gallons of the concentrate and 2 gallons of distilled water. Mix equally and that gets you freezing protection to -35 degrees.

Zerex G-05 is what we use in our shop for only newer Ford and some Chrysler vehicles. If a customer specifies OEM coolant for their Chrysler family of vehicles, we use MoPar coolant. We do not use the Zerex G-05 in any GM vehicle.

Greg Gore

Dexcool is better antifreeze because the organic chemistry formula was engineered to keep cooling systems cleaner. Blocks won't rust and the aluminum parts stay bright and shiny.

ch@0s

It's all about maintenance and dont mix incompatible coolants.

crowz

Still sticking with the green for all my stuff. Bmw fanatics say bmw blue coolant only. 343k miles on one car and 280k on the other with the green and works fine. Also all my bmw's still have the factory radiator etc on them and that's rare.

Ford falcon of mine has had green in it for over 45 years. So far so good.

My gm products all have green in them. I ditched the coolaid crap asap after buying them. All have over 200k on them and are fine.

My superduty ford diesel has 340k miles on it with green coolant. Water pump on that one for example lasted 285k or 295k miles.

Just not willing to buy the need for "new" antifreeze. Probably part of being old myself I guess.

But one thing I do make sure of when switching to the green coolant is to flush the old coolant out. Dex and green do NOT mix.

desertmike1

Congratulations on your new Radiator, did mine a couple years ago..

Use the Factor fill Antifreeze for your vehicle, either one will play nicely with your new Radiator..

RollaMo-LT4

Not true at all.

The '96 Corvette came from the factory with Dex-Cool.
I have just over 121,000 miles on mine now and still using it.

Not sure about the '95, but the '96 for sure came factory filled with Dex-Cool.




And most importantly This.

Greg Gore

The green is old technology but if you keep up with the maintenance, flush and change it, it should be OK. Dexcool was specifically developed for alloy cooling system parts and is superior for aluminum heads on iron blocks.

PLRX

Where did you get that information?

GM has been using DexCool for 20 years. It does not harm anything as long you do what it is to be done.

Even on my 92 I flushed the system, added Dex Cool, and never had an issue.

I use Dex Cool, the C5, C6, and C7 use Dex Cool, and other car manufacturers use Dex Cool.

NOW, DexCool IS NOT TO BE MIXED WITH ANYTHING ELSE BUT DISTILLED OR DEIONIZED WATER.

Paul Workman

As I understand it* the issue isn't the aluminum, but possibly the head gasket material (AND mixing Dex with "green", of course).

*There is definitely an issue with Dexcool and the head gasket material used in the LT5, which may also be a factor in the SBCs of the time as well???

Dexcool article

Best to stick with the manufacturer's recommendations. This is a "biggie"!

Greg Gore

When the engineering team documents their work and signs off on a design after the R&D work it becomes part of the "system." When you change something in the system or deviate from the way it is supposed to be you are on your own.

crowz

Dexcool has issues but gm and Texaco both say the coolant is "ok". The normal blame is given to air in the system causing sludge build up. So I personally wont run the junk. Green works fine even when low on fluid. Dexcool causes sludge when exposed to air. Its nearly impossible to get all of the air out of an l98's cooling system. Its not designed to be bleed. So common sense says dexcool sucks for l98 applications. Lt1 applications are fine if you get all the air out. Guess what, no one ever gets ALL the air out. But you do usually get enough out to keep from having problems. Usually.

My logic is why bother with a coolant that can cause sludge build up if the moon doesn't line up right......

That said to each their own. After all its your car and what you run in it is your business but that's why I wont use it.

Some gm vehicles had so many problems from it there were class action lawsuits about it. Blazers caught the brunt of the damage.

Search for dexcool sludge on the this very forum for instance.

Greg Gore

There's never any air in the system with the reservoir system when the reservoir coolant level is properly maintained. Like not changing the oil or checking tire pressures owners are sometimes guilty of neglecting to check the coolant overflow reservoir as the water in it evaporates. When the reservoir is allowed to get bone dry you do then have air in the system. Class action suits come about because they have not figured out how to make cars idiot proof yet. Lemon cars do not exist however lemon owners are another matter.

WW7

The bottom line is, use what you want , but if you switch coolant types, just make sure you flush the system completely, leaving no trace of the old coolant ...Not doing this can cause problems with your coolant turning to a jelly like substance......WW

Richard Raichert

[QUOTE=PLRX;1588768131]Where did you get that information?

GM has been using DexCool for 20 years. It does not harm anything as long you do what it is to be done.

DexCool might have come out after my 94. My owners manual lists the spec and the part number which is "green". It states in the manual that to not use anything that will react to the aluminum engine parts. (kind of vague). Should not have said to not use DexCool but our regional GM service manager of 25 years said to stick with the green. When I had mine flushed it had orange sludge in the overflow/recovery tank. Don't know if DexCool is orange or if something else was used.
This is an interesting thread because Vette high collant temps are a common topic.

crowz

[QUOTE=Richard Raichert;1588781362]Yep that orange sludge is the wonders of using dexcool

RollaMo-LT4

Nope, lack of maintenance is.

No orange sludge in mine, never has been. Over 121,000 miles now.

And there are literally millions of other GM vehicles on the road today with hundreds of thousands of trouble free miles using Dex-Cool.
Class action law suit or not, the number of trouble free vehicles far outweigh the number that had issues.

As mentioned previously, the main issue comes with two incompatible coolant types are mixed (which is basically the same as lack of maintenance).

And to point out, I would never want to start using Dex-Cool in a system that came with the old style.
Same as I wouldn't go back to the old style in a system that came with Dex-Cool.

The '96 Corvette for sure came from the factory with Dex-Cool.
No issues at all with that car.