Ok, when I first start my car up it knocks then it goes away. It's not rod bearings I dropped the oil pan and checked everything out and replace the bearings anyway. Car is not what it use to be a few days ago ever since i heard this knocking although my valves are EXTREMLY loud. Could the valves be really loose that its causing knocking & loss of power? The knocking only occurs when first started up last for 3 seconds or less. when holding at 3,000 rpms it dont knock just hear LOUD valves.