Valve train

THE VALVES ARE NOT ADJUSTABLE. THAT MOTOR SOMETIMES DOES HAVE CAM WEAR PROBLEMS WHICH WILL MAKE THE (VALVES NOISEY). THE BLACK BOX ON THE SIDE OF THE INTAKE MANIFOLD IS THE INTAKE RUNNER VALVE WHICH CONTROL FLOW IN THE INTAKE MANIFOLD, THE FLAP ON THE VALVE BREAKS OFF AND THEN IF FLAPS AROUND AND CAN MAKE NOISE. RECOMMEND HAVING IT CHECKED OUT.