I had Prestone antifreeze for a while in one of my "A's" years ago and it would foam up too. I switched to the Sierra brand antifreeze and no more foaming. Sierra is more ecological friendly and is even green in color.
However, for a car that sounds like it has not been driven for a few years.
I'm sure there are more reasons why it is foaming then just the type of antifreeze in it. The whole coolent system needs a thorough cleaning
most likely.
Bob-A
