Get a power flush from the dealer or a place that has the machine. I got it done to mine and fix my low heat from my HVAC system.

 

Wow! Lots of info on the coolant!! I never put that much thought into it since I had my '94 S10, that truck got the right coolant, oil, filters and @ the right times. Nothing was left to chance, I even changed the fuel pump @ 100,000 b/c I didn't want to break down. Truck went way past 250,000 and is living out it's golden years in Mexico..lol no joke. I will flush and stick to the good 'ol green, I just don't trust the sludge I see from the dex.
Mouse