1999 Jeep Cherokee TAPPING NOISE DURING ACCELERATION

HI JUST NEED TO KNOW WHAT WOULD CAUSE TAPPING SOUND WHEN I ACCELERATE TAPPING STOP WHEN IM IDLING OIL PRESSURE GOOD NO ENGINE LIGHT JUST LOUD TAPPING UPON ACCELERATION NEW WATER PUMP, NEW RADIATOR,HEAD GASKET, TIMING COVER GASKET,HYDRO LIFT,OIL FILTER ,REAR BRG SET,ADVANTAGE ELECT, & TIMING CHAIN ALL NEW PTS ON TRUCK OIL PAN SCREEN CLEANED. PLEASE HELP!