In this paper, the valve noise is analysed by both analytical and experimental methods. Assuming that the valve noise is mainly transmitted by the structural vibration of engine head cover, the dynamic characteristics of engine head cover are examined by Finite Element Method and by Experimental modal analysis technique. Then the transmitted valve noise is estimated with the FEM model when the actually measured valve impact force are applied to the engine block. The estimated valve noise was directly compared with the measured noise level when the valve train is driven by a motor. Also it was tried to diagnose valve train motion by examining valve noise. It was found that the power spectrum of the measured valve noise can only tell whether the whole valve motion is in normal or in abnormal but it is difficult to futher investigate which valve is in abnormal. But the valve noise measurement in time domain can be used to detect which valve is in abnormal motion.
