had the coolant flushed and refilled on the old bugger. I told them I wanted the green stuff not the dexi-cool. The water in it was mainly brown so it was hard to be sure what was in it to start. It is definately green glycol now.

I believe this change was okay as long as it was flushed well.....right?

The car has 1998 minifold covers on it so it probably experienced troubles long ago.

Should be fine as long as the flush was complete.

Is that an AC Delco UIM? You could have problems again. Keep a sharp eye on it.