ricknyc23

I know most of you guys recommend Dexcool, but Ive read that it has caused problems. Anyone using Preston or any other coolant?

NatB

Suggest staying with the formulation designed for the C5.

lucky131969

JW Motorsports

Prestone makes a Dexcool coolant

LoneStarFRC

And that is wrong.

Use Dex and don't worry about it.

Bill Curlee

I’ve owned a 98 Coupe, 02 ZO6, 06 Coupe, 2011 GS! They ALL have DEXCOOL or equivalent. Dexcool is an ORGANIC ACID TECHNOLIGY (OAT) coolant. NONE of my cars have ever experienced a cooling system issue as a result of the coolant! PERIOD!

As long as the system is properly maintained, is NOT mixed with a GLYCOL “silicate” (GREEN) coolant and has a sealed reservoir tank with the proper PSI cap, you will be ABSOLUTY fine.

If you want the best cooling system efficiency, drain ALL the coolant! Refill and drain the system with fresh water until it runs clean/clear. Drain one last time and refill the system with the PROPER ratio DEXCOOL & WATER. Depending on where you live DEEP SOUTH or ARTIC TUNDRA North East; you can use more or less antifreeze to water. Guys that live in places that seldom see temps lower than 32 deg don’t need coolant that protects down to -35 degs!

I always use distilled water to dilute the coolant.

Make sure that you use a hydrometer and get the CORRECT coolant to water ratio to keep the engine from freezing or boiling over.
BC

Bill Dearborn

It caused some problems in engines built more than a decade ago. Those engines had seals that were not compatible with DexCool. The only thing left out of that small number of incidents is a so called class action law suit that doesn't have much oomph behind it since there are so few members of the class. GM has produced millions of vehicles with DexCool in them and only had issues with a few engines. I have never had any issues since I purchased my 97 Vette which was the first car I had with Dex in it. I keep the coolant in the radiator until I reach 5 years and change it although it still looks like new. My daughter let her 02 Olds go 6 years before I insisted she had to change it. I have never heard of anybody with a LS engine having any cooling system problems due to DexCool.

If you go to the old fashioned green coolant your coolant change interval will go to two years instead of five and you will have more coolant issues. In close to 50 years of having my own cars I had lots of cooling system issues when the green stuff was the only stuff you could get. Didn't matter who made it. I haven't had an issue since I got rid of my last car with green Prestone in it in 1999.

Bill

jrose7004

Me too!

leadfoot4

I've owned 4-5 GM vehicles that have had DexCool in them, the only one I'm unsure of is the '93 Caprice that we had for several years, but traded off 11 years ago. I change the coolant every 3-4 years, and have had no issues at all. My Z-28 is 15 years old, no issues. My C-5 is 10 years old, no issues.....

1blkc4

I always drain the dex coolant out of all my gm cars and fill it up with the prestone coolant for all makes its yellow

Carcass

If Dexcool actually caused problems in the C5,it would have been discussed many times on the forum-
The rumor has been discussed over and over,actual problems being caused by Dexcool,not so much....

LoneStarFRC

This is an urban myth/legend that will not die. A classic case of "A little bit of knowledge can be a dangerous thing" and people continuing to blindly believe what they see in "print" on the inter-web. Dex-Cool has never caused a problem in ANY cooling system. Period.

Certain few makes/models of GM cars/light trucks experienced cooling system failures several years ago from improperly designed gasket material. None were Corvettes btw.

Vettmann17

I'm the original owner of my 2002 and have always used Dexcool and never had any coolant related problems. Why would anyone want to switch away from a proven product, your just looking for problems. Stay with what your manual recommends and don't worry about it.

c4cruiser

There are lots of "universal" coolants on the market that are advertised for use in just about any vehicle. These coolants are about the same price per gallon as traditional ethylene glycol (green) or Dexcool (red) coolants. Dexcool is the factory fill since '94 or 95 in Corvettes (and all GM cars for that matter. So why not just continue to use Dexcool?

The Havoline Dexcool brand is the same stuff used by GM. Buy the jugs of concentrate and add distilled water to make up the necessary 50-50 mix for protection to about -35 degrees. I have seen both the pre-mix bottles and the concentrate bottles for about a dollar difference, so it makes sense to buy concentrate and get distilled water at a grocery store for a buck a gallon.