Why is there Sludge/Slime in my Radiator? – AMSOIL Blog
Inorganic salts deplete quickly – typically in two years or less – and are on the environmental watch list. Once depleted, they are the source of common cooling-system problems, like scale deposits and sludge/slime. Low-cost “green” coolants are the source of several problems, such as radiator sludge/slime and scale deposits.