I can't find an answer that I like doing a Google search. Does anyone know a definitive way to tell if my new used car has Dexcool, or if they switched it to ethylene glycol? It's very clean and I don't want to dump it if it's conventional antifreeze. If it's Dexcool, is there a prescribed procedure for switching to ethylene glycol? I mean besides flushing, is there a chemical that needs to be used to remove all traces of Dexcool? I feel that maybe switching to conventional antifreeze in my truck might have contributed to needing to replace my radiator due to clogging.

I saw that I could use my refractometer and whichever scale lines up would indicate which coolant, but how could that possibly work if I don't already know the concentration?

 

I don't the answer on how to find out what is in there. I've got an old truck that had green antifreeze when I bought it and replaced it with the same when shortly after I bought it I had to replace the radiator due to a leak. I've since added a bit of some universal coolant because that's what I had on hand. 🤷

Do you know how old the coolant is? It may be time to go ahead and replace the coolant anyways. I would imagine a drain, fill with water, flush and replace with coolant of choice would suffice for this?

 

I think it would be the safe thing to do, but is flushing with water guaranteed to remove all traces of the bad components of Dexcool?

 

Not sure TBH. You can do a double flush and/or add that flush additive they sell?

I did a coolant flush with the additive around 120k and shortly after that my heater core started leaking. It may have been a coincidence of course...

Also, I assumed you were going to run Dexcool? Dexcool is all I run on my GMT800s. I usually run it about 75k-100k as a drain/refill or if I have to do a water pump or something that involves draining the coolant.

 

Why would you get rid of the dex? It’s fine, the problem was with the GM stop leak tablets they put in it lol

 

I have a very small leak and I don't want to do anything about it until probably next summer. I want to keep topping it off like I have been, maybe a pint a month, but with antifreeze instead of the distilled water that I have been adding. That won't work too well in the winter.

 

I almost never buy the "premixed" coolant, but in your case, maybe that will work for topping off due to your small leak, no? Or just mix your own and use that?

What concentration do you guys run up there? Our winter climate is pretty mild here and I've always ran 50/50, and I think that's what the premixed coolant they sell locally is IIRC.

 

Exactly. If I knew what coolant is in the car that's what I would do.
And yes, 50/50 is recommended everywhere as the best balance between heat removal capacity and freeze protection.

 

TOP up your system with ANY BRAND of "Universal " ALL-Makes coolant.
NAPA, Oreillys, Prestone, ect all brand yelow Universal coolant, suitable for mixing with what ya got.
It was just an early fluke, with the first 4 or 5 years of the Dex-Cool fiasco, where they had some GM used fucked up additives that would cause troubles-- Supposedly-- when cross contaminated or mixed with conventional antifreeze.

 

Yup, I'll second what @Fullpower is saying. He's one of the many universal coolants out there. https://www.chevronlubricants.com/en...zecoolant.html

If you read the Product Data Sheet (PDS), it basically says you can use it on any vehicle and coolant type: https://cglapps.chevron.com/sdspds/P...&docFormat=PDF

Footnote 1 mentions silliciate containing coolants. I have no idea what manufacturers require that stuff or what that is, but I doubt it's our GMT800s, LOL.