Saab: 96 saab 900s, saab 900 s, saab 900

Question
I have a 96 Saab 900 s that stalled out and is now making a loud
knocking noise. Any suggestions?  

Answer
Jayme:
 You said that the car "stalled out"; Can I assume that you got the motor running again? If so, can you describe the sound more completely, such as:  is it louder when the engine speeds up?  Does the knocking speed up as the engine speeds up? Does it get even stronger when the engine moves the car (as opposed to just idling)?
 Does the knocking change with travel speed?

  These can help pinpoint the problem more precisely. In general, though, any "loud knocking noise" originating in the engine spells big trouble, that is, a dying engine.