Cliff Harris

You neglected to quote the part of my post where I said putting in the Dexcool happened in the mid '90s. That was a LONG time ago. That was right after it was introduced and nobody knew anything about it. The reason I switched was because it claimed 5 year coolant change intervals. I distinctly remember it said, "compatible with all cooling systems" on the front of the container.

I will say that ever since then my coolant has always looked rusty. I tried a lot of things, even trying 3 or 4 different flushing chemicals but none of them fixed that. The only thing that finally resolved it and gave me green coolant that stayed green was the 10 or so flushes I did with plain water. I was driving the car every day and draining it every night. It was a pain but it worked.

MikeT 90 C4sixer

Sharp observation, Cliff. I dont always copy all of the quote when i reply. Try to keep things simple. I to remember when Dexcool first came out. Might have been a sales or marketing pitch, saying it was compatible with all cooling systems. But like you said, not much experience with it back then. I guess some folks were the guini pigs!

Tom400CFI

It IS compatible with all cooling systems...just not other coolants. So any system that has some left over in it, be it in the reservoir, parts of the radiator that never really drain, the heater core...where ever, that can cause an issue. But as a fleet manager, I've run it in TONS of different things; diesels, different gas engines, brands, makes models...I even run it in my snowmobiles. It's compatible with systems...but not other coolants.

MikeT 90 C4sixer

quick update....got my new gasket set today. The intakes are Felpro, and they have a restrictor in the rear section.....although not a metal one like the OEM, just more gasket material. But the little opening is surely bigger than the stock opening. i didnt measure it but at least twice as big. so more coolant is going to flow when i am all done with this project.