drgage

I was almost done repairing this Oldsmobile I've been working on when I noticed something.
At first yes, the oil light went out and I thought everything was ok. Then I heard a 'knocking' noise. It began to get louder. That's when I realized that I needed to prime the oil pump for it. I tried that. But the car is still making the knocking noise and the oil isn't getting to the pump properly. I'm afraid that if I keep cranking the car it will mess everything up totally.
What can I do to fix this problem ?. I've tried everything I know to do !.
Any suggestions ??.
Edited to Add - The oil isn't getting to the oil pump the way that it should now. It was doing fine at first. But something somewhere happened and now the car is making a knocking noise and the oil isn't getting to where it should be. Can anyone help me ?!.