Originally Posted by Lesmyer

Sounds like your father's Lesabre had cooling system problems before the Dexcool was mistakenly added, probably without flushing. Idiots work in dealerships too! Sounds like you probably have a mix in your Blazer as well.

To me, it seems that Dexcool itself was not the cause of your problems. It was mis-use of Dexcool. Dexcool used properly works just fine (except as we all know the problems on original plastic intake gaskets with original Dexcool). But the need to not mix it with old style antifreeze and to keep air out of the system has given it a very bad rep.

I agree that your 1993 should not have Dexcool in it - but not because Dexcool is inherently bad. Just make sure what is in there now is completely flushed out. That may or may not be possible if it is gunked up too much.