Abstract
<jats:p>Background. Various methods are widely used in diagnosing the technical condition of automotive engines, but most require highly skilled personnel and sophisticated equipment. Vacuum diagnostics, based on measuring the vacuum in the intake manifold, is an accessible and effective way to assess the condition of the engine and auxiliary systems. Purpose. To explore the potential of using a mechanical vacuum gauge to diagnose the technical condition of the cylinder-piston group, valve timing systems, valves, and other engine components of various designs. Materials and methods. A mechanical pointer vacuum gauge was used in this study to measure the vacuum at various points in the vacuum systems of gasoline and diesel engines. The dynamics of the instrument readings were analyzed, faults were modeled, and a comparative analysis was conducted with compression diagnostics, computer diagnostics, and oscillographic methods. Results. The method demonstrated high information yield for identifying air leaks, valve malfunctions, valve timing issues, ignition problems, and other faults. Practical recommendations for interpreting vacuum gauge readings and a table of reference vacuum values for various engine types are provided.</jats:p>