[MikeK]

Originally Posted by walkerlakeprinter

. . .Since the plugging is obviously made of corn, is there anything that would dissolve it so it could flush out?. . .

Yes but not readily available. The corn kernels have a tough cross-linked cellulose structure. Canned corn (think 'Niblets') will stay in the can water forever and not dissolve. You need two enzymes, endocellulase and exocellulase to break it down to soluble sugars. They use that stuff in some corn to ethanol conversion plants to increase efficiency, as yeast cannot touch cellulose as a food source but loves sugar. Getting just a quarter pound of it (plenty!) is not easy.

You would need to flush out as much as of the present goop as possible and fill the system with a near pH7 mix, kept well below 90F and circulated without the engine running for many hours.

That said, several rounds of the Drano and flushes to clear the block, followed by pulling the radiator and having it hot tanked and internally inspected with an endoscope may be the way to go.