Tapping during idle and acceleration/valve tap

Hello, Mitsubishi, at least in the past, has been known for valvetrain noise and leaking valve seals. This may be a bad lifter, or multiple bad lifters, but you also may need the valves adjusted - depending on which engine you have. Also, if the oil and oil filter are incorrect for the vehicle, low quality, or due for replacement, consider changing to the oil recommended by the owner's manual. Also, if you have variable valve timing, you may be hearing the actuator clicking, which would indicate it may be failing.