The balancer belt broke and I replaced it and now I have a vibration at idle and low rpms. I also noticed a knocking noise in the valve cover since i replaced the belt. Can someone help me out. Is the a position fro the oil pump pulley to be aligned. and is it possible the balancer is out of alignment. what might be the noise?

 

Yes, you'll need to get the front and rear balancer pulleys aligned when installing a new belt; otherwise, you'll experience some vibration. If you search, you'll find some pictures and how to go about timing the balancer pulleys.

 

Would also be a good time to replace your motor mounts if they are old, worn, and broken.