Abstract
Type Diagnosing and detecting malfunctions in internal combustion engines (ICE) is not an easy task due to their complex design. Timely and high-quality ICE monitoring allows performance to be maintained and prevents breakdowns. Vibration and acoustic analysis is a powerful and informative tool for detecting faults even at an early stage. This article considers a method for determining the main malfunctions of the valvetrain (VT) (tightness of the "valve-seat" interface, thermal gap in the valve drive, valve opening and closing phases) by measuring and analyzing vibroacoustic pulses caused by the operation of individual engine elements. The maximum amplitude and the moment of vibration impulses are used as signal parameters. For the reference signal of the piston, the top dead center (TDC) of the cylinder under study, a vibration pulse from the impact of the piston on an elastic tip placed in the combustion chamber is taken. This technique makes it possible to exclude the external influences and inaccuracies associated with a change in the geometry ICE elements.