Chevrolet Repair: Engine Knocking, 1997 chevrolet cavalier, chevrolet cavalier

Question
I have a 1997 Chevrolet Cavalier. It has a 2.2 engine.It is a front wheel drive. We change the oil every 3,000 miles.The car has 209,000 miles on it. I'm getting a knock comming from the engine.I am unable to tell if it is comming from the bottom end or the top end. I thought it may have been the oil pump. I pulled the valve cover and it is getting plenty of oil to the rockers and to the top of the head.My oil light is not on either. I'm going to pull the oil pan to see if I have spun a bearing or maybe I have a loose piston cap.My question is, if I have a flat spot on the cam or crank would this cause this knock. It sounds like a bent push rod but I pulled all the push rods and none were bent. Could the sound possible be a froze lifter?

Answer
Hi Andre... yes you could have a stuck lifter....but it would sound more like a tap not a knock...if you suspect a stuck lifter pull rocker cover and roll engine over and watch rocker arms.the stuck one should become loose once engine rools past stuck spot...hope this helps