Originally Posted by Flatlander
I see in a previous post quoting the GM'* engineer that the problems with the 4.3 liter engine is because dex cool does not provide protection for cast iron cyl block and heads. What do you think our boneville engines have? are they not cast iron block and heads also? Another thing he states that the coolant should never be allowed to go low. On both of the 4.3'* I am talking about the coolant levels in the overflow tank always showed full and were never allowed to drop below the cold line. Friends of mine that own an independent garage have also seen problems with dex-cool plugging up systems. Maybe it is okay in aluminum blocks and heads but I will see how my parents 03 Cavalier'* cooling system lasts.
Did you read the entire paragraph? He did not say that Dex-Cool does not provide protection for cast iron cyl block and heads. He said it won't provide protection in cast iron blocks and heads if it is not kept full
. Full has nothing to do with the overflow tank. A bad cap could leave your tank full but you radiator low. Then you will have a problem. You CANNOT allow air in the system.