Diesel engines have various parts such as combustion systems, drive systems, intake and exhaust systems, cooling systems, etc. When defects such as deterioration of lubricating oil and deformation due to heat occur, metal-to-metal contact occurs and vibration and noise tend to increase. In the past, we measured the vibration generated by an engine and established a method to estimate the surface condition of engine parts without dismantling by machine learning. In this study, we will verify the improvement of the reliability of the prediction data and the optimization of the measurement time at the time of inspection．
