Alternative diagnostic method applied on marine diesel engines having limited monitoring susceptibility

The paper presents a method of technical state evaluation of working spaces of a marine diesel engine at the limited control susceptibility. The method foresees making a diagnosis of the engine’s working spaces on the basis of measurements of the exhaust gas pressure in the channels connecting engine cylinders with the turbocharger’s turbine. Diagnostic measurements are carried out at representative (comparative) steady loads depending on floating conditions. In the beginning of the article, the research objects are characterized, i.e. a Zviezda marine main engine M401 type and Detroit Diesel marine auxiliary engine DDA149TI type. Then, diagnostic measures used to identify the condition of the considered engines are defined. Moreover, selected results of diagnostic tests carried out on the engines in current operation on warships in the Polish Navy are demonstrated. The tested diagnostic classifiers confirmed that the elaborated method could be successfully applied for the engines not equipped with indicator valves.