[LNP]

Originally Posted by 72SB

LNP

I understand your concern about Dexcool. Yes GM had issue with it as I mentioned. My 96 came with it and in short order brown sludge (within a year IIRC). The car was under new car warranty and the dealership flushed the system and replaced with green which to this day I still use in that car although it is now a 383

My understanding was GM started all models in 96 with a 100k mi full service Maintenace schedule so needed a coolant that would last that long. Unfortunately, the Dexcool was not up to that task and also the anti-leak pellets GM put in cooling systems then really did react chemically to Dexcool which turned it into brown sludge. I don't know when Dexcool was reformulated, but it was

My neighbor was a mechanic for state road Maintenace (CalTrans) and he said they took Dexcool out of all their trucks as they had issues with the sludge and said also plastic components in cooling system got brittle because of it

With that said my 72 C10 6 cyl had Dexcool in it when I got it. Assume PO ran it. I have continued to use it without issue

The problem with it or was then was they replaced the silicates and phosphates that was found in regular anti freeze with new chemicals to make it last longer. Man that didnt work. lol These chemicals ate seals degraded plastic which was used and still is for intake manifold gaskets. They may have changed those chemicals with different ones presently I dont know. But if its working now for you it must be a different formula. Hope you never have any issues with it for me I will stick with green anti freeze.