THAT SOUNDS ALOT LIKE A
THAT NOISE AND BEHAVIOR SOUND VERY MUCH LIKE A LIFTER NOT SEALING UP CONSTANTLY, A BIT OF DEBRIS STIRRED UP FROM THE CHANGE GOT INTO THE LIFTER SEAL AND ALLOWS IT TO LOOSE OIL PRESSURE AFTER ENGINE COOLS, THEN IT WILL KNOCK WHILE COLD, IT PRESSURES UP AFTER IT WARMS UP...