Best of Deals Car Reviews Repair Shops Cars A-Z Radio Show

Green coolant in a 2001 Chevy Lumina?

My mechanic changed my coolant today and used green coolant instead of Dex-Cool. The manual says Dex-Cool, but my mechanic said I don’t need to use Dex-cool anymore because my car is old and has 133k miles. He thinks green coolant is just as good if not better for an older, high-mileage car. (This conversation tool place after the job was done, so I didn’t get a vote, not that I have a strong opinion on the subject.)

What do you all think of my mechanic’s perspective? I’m just looking a second opinion.

A little more info: The last time I had my coolant changed was at Jiffy Lube and they didn’t use Dex-Cool either. They used a yellow coolant which I believe they described as a universal coolant that could be used in any car. That was a few years ago.

I had a 2006 Chevrolet Uplander and had the Dex-cool replaced by green coolant two years ago when the van had 60,000 miles. I did this just before I sold the Uplander to my son. He now has close to 100,000 miles and has had no cooling system problems. He just had the coolant replaced again with green coolant.
My independent mechanic, who has never given me bad advice, recommended replacing the Dex-cool with green coolant. I really don’t see any advantage to the Dex-cool. It is supposed to be good for a longer time period but I would rather have the green coolant and change it more frequently.

As long as someone flushed all the Dex-Cool out, you’re golden. In fact, I recommend everyone ditch long-life coolant as soon as their vehicle is out of warranty and go to the green universal coolant your mechanic used.

There have been horror stories about what can happen when you mix Dex-Cool with other coolants, but they are frequently disputed. Still, I would make sure the Dex-Cool was all flushed out for peace of mind.

The green will be a huge improvement.

There are horror stories about using Dex-Cool also. A lot of gasket failures.

I had a 96 Caprice that had Dex in it, I tried to flush it all out many times… However every time I refiled it with green it would turn brown very quickly… I was told that it is next to impossible to get dex out of a system 100% becasue it bonds to the metal parts…

For what its worth, I now have a 98 Buick. It still has Dex but it has been flushed at least twice in its 125,000 miles (once by me the other by the original owner)… I dont trust it for as long as they say you can.

I had the Dexcool replaced with Prestone green antifreeze when the intake manifold gasket was replaced on my 2000 Blazer back in the beginning of 2004. I drain and replace the coolant every 3 years or so. After 8 years I’ve had no problems with the Prestone coolant.

Ed B.

Your mechanic did you a big favor.

The problem with Dexcool is it’s the first Organic Acid Technology antifreeze or OAT antifreeze. If the level of the coolant drops in the cooling system and air is introduced into the cooling system the Dexcool becomes acidic and begins to corrode internal engine components. You then end up with a rusty sludged up cooling system. If you’re one who opens the hood once in a while and checks the fluid levels you won’t have a problem with Dexcool. But if you’re one who never opens up the hood and depends on others to service your vehicle, then switching to the green or universal coolant is a good idea.

I have people who bring their new GM vehicles to me as soon as they’re out of warranty for me to flush out the Dexcool and replace the coolant with the universal coolant. Which is called Hybrid Organic Acid Technology coolant or HOAT coolant. Where air in the cooling system doesn’t cause the coolant to become acidic.


Thank you all for your comments. I’ve learned something new.