I have a 2004 chevy cavalier, and bought it in 2005 with 23k miles, I know for a fact that the coolant has never been replaced
Now, I have 70500 miles, and the manual says that you should replace the coolant at 150,000 miles or 60 months, whichever comes first
Well, it has been more than 60 months, and I don't know if I should replace the coolant, or I'm good until 150k miles?
I would replace it. It is not going to hurt. It is well over the 60 month mark. Just make sure you put the correct kind back in it. If you decide to swap to the green coolant, then make sure you flush all the old dex-cool out of the system.
I would change it. Maybe even flush the system out while your at it.
Coolant becomes acidic when it get old and will dissolve aluminum and other materials.
On the inside my car looks like a fighter jet.