Originally Posted By: Lubener
You won't get any as long as the cooling system stays full. but drain the fluid an corrosion starts immediately, and keeps corroding for months after refilling
Doubtful.. [/quote]
https://www.motor.com/magazine-summary/c...-or-orange-or/# 2 excerpts from the article, but it's interesting enough to read all of it.
Quote:
The inhibitor 2-EHA works well in hard water and is more effective than sebacate at lower pH levels (when the coolant moves from the alkaline end toward the acid side), particularly for cast iron. Well, GM has a number of cast-iron engines. When there's a low coolant level in the coolant passages, the exposed cast iron rusts. Apparently, that rust is washed away later by flowing coolant, and is deposited in the heat exchangers. It eventually produces the rust powder problems that have been so widely observed (see Motor's August 2002 issue at
www.motor.com). Why does the coolant level in these engines drop? The original radiator cap design was blamed for some of the issue, but there probably are a number of causes, including owner neglect and normal seepage. However, the rust powder issue is not a problem that was observed with the previously used conventional American coolant.
Quote:
If you're replacing aluminum parts on an engine, such as a water pump or even a new cylinder head, remember that part's coolant passages have not been protected. In those cases you should perform a complete coolant exchange.