Sorry if this has already been posted but I didn't see anything in my search.

My 2000 Blazer ZR2 doesn't say anything underhood about Dexcool and had green stuff in the overflow bottle. Same thing with my stepmom's 03 ZR2.

However, my dad's 96 Jimmy says to use Dexcool in at least two spots (one of which being the radiator cap itself) and obviously uses Dexcool.

did GM only use Dexcool in certain vehicles or something? I'd believe the guy I bought my truck from didn't pay attention and used the wrong stuff if that's the case, but my stepmom's truck had 30K on it when she bought it, and the coolant hasn't been touched since.

 

both of those should use Dexcool. One way to tell is by the cap on the overflow tank. The letters are a pinkish color, If it took green the letters would be green. If you switch back to dexcool make sure you flush the system with a lot of water to get all the green out.

 

I'll be switching back in mine, I'm sure. Now I'm concerned that the previous owner was refilling and mixing dexcool and green...