A modern vehicle is a system of high-precision systems. In particular, over the past 20 years, the gas distribution mechanism (GRM) has been structurally released from any adjustments. However, alongside with that, the elimination of the adjustments did not entail a decrease in the number of GDM failures. The analysis of a number of works shows that the GDM mechanism accounts for more than 30% of ICE failures. The problem lies in the high sensitivity of modern engine systems to the oil drain interval, fuel quality, timeliness of maintenance, etc., i.e. to carrying out of routine activities. According to the analysis of the operating conditions of modern vehicles, the regulations are significantly violated in more than 50% of cases, which results is a considerable reduction in the service life of vehicles. In this connection, it is relevant to develop diagnostic methods allowing us to determine the degree of wear of engine components at all vehicle operation stages. One of such methods is the vibro-acoustic method. The research aims to develop a methodology and method for diagnosing GRM by analyzing vibration parameters together with a pressure signal in the cylinder, the angle of the ICE crankshaft. As a result, the mechanism for recognizing the fault conditions of individual GRM valves is determined. A set of diagnostic tools for the selective diagnosis of GRM elements has been developed. A methodology for determining the GRM phases and thermal clearances in the valve drive using the nondemountable method has been created.