Coolant System Green Goo

[cmillsap]

David,

Yes, I remember Gary Spires and a lot of other opinions from other “experts” especially on the subject of mixing coolant types. I went away more confused than before about coolants. Everyone had their own different opinion.

I don’t see anything wrong with running the green conventional low-silicate coolant (IAT) in our DD S-60 engines. The important thing is to make sure the coolant is maintained at the proper mixture, freeze point and PH level to protect the cooling systems of our heavy duty engines against corrosion, cavitation, liner pitting, freezing and boilover.

The pre-charged SCA timed release coolant filter sized properly for the system’s capacity works well to help maintain the proper SCAs for a certain period of use. But coolant condition needs to be checked regularly and changed periodically.

Until all these new-fangled coolants came on the market, the green stuff was what everybody used. The coolant system in both yours and my bus was probably filled with it from the factory. Every bus that I have owned had the green stuff in it when I bought it. I changed 2 of them over to OAT because I thought it would be better for my engine. But if it was, I didn’t see much advantage except it allowed a longer time between coolant changes.

My bus has probably run on the Green Stuff for over 154,000 miles with no issues (that I know of) related to or caused by the green coolant. It runs cool and the DDEC shows no codes of ever overheating. The coolant is clean with no discoloration. It’s been in there for two years and 12,000 miles. I’ll change it at 25,000 miles or next year. Obviously, I can’t check the cylinder liners for cavitation and pits but I’d bet there are no more than if it had been running with OAT for 154,000 miles.

While I appreciate the suggestion to change to OAT, I see no reason to change from the coolant type that’s probably been used in it for 14 years and 154,000 miles. Now, if you are saying that engine damage is more likely to occur if I continue to use the green stuff, I’m certainly willing to listen.