IT SHOULD BE EASY TO DETERMINE IF IT IS COMING FROM THE OIL PAN OR THE VALVE COVERS. BY USING A ROUND PEICE OF WOOD LIKE A SHORT (16") PEICE OF A BROOMSTICK(MOM'S FAVORITE), PRESS ONE END INTO YOUR EAR AND THE OTHER ON THE VALVE COVER OR OIL PAN. CLOSE YOUR EYES AND LISTEN CAREFULLY. SOMETIMES YOU CAN EVEN PINPOINT THE NOISEMAKER FROM OUTSIDE THE COVER! LET US KNOW HOW THE SEARCH WENT. GOOD LUCK AND I HOPE IT'S SOMETHIN' CHEAP.