Saturn Repair: 1997 sl2, oil flow, rebuilder

Question
a friend of mine just rebuilt the motor to his 97 sl2 it has 95,xxx miles on it the reason for the rebuild was the
number 3 and 4 bearings spun he only has put 2,000 miles on it since and he now has a lower engine knock again any sugestions on what could be causing this problem

Answer
It could be that the oil pump screen could be partially plugged. I've seen that happen before where the rebuilder cleans off parts with a rag and eventually the fuzz ends up on the screen thus  restricting oil flow. Also one of the bearings could be torqued incorrectly which would not allow oil to go through the oil passages correctly.