Why does my engine make terrible knocking noises now?

What is your question?

My 'Mitzi' is a 1995 Mirage. It has only 77k miles on it (doesn't see much action does it? lol). About a week ago, it started making this terrible noise, I originally thought it was an exhaust leak near the front. However, my husband (who was a mechanic for years) took a good look one day and discovered the crankshaft is vibrating terribly. He researched it and found there might have been a recall regarding the crankshaft (apparently they tightened the crankshaft too tight at the plant). I have not been able to find any such recall. Can you help me??