In this paper, in terms of diagnostic tests, functional systems composed of a technical object that is marine diesel engine piston were presented. This decomposition enables the identification of diagnostic systems, where failures occur most frequently and those whose failure may cause serious This decomposition enables the identification of diagnostic systems, where failures occur most frequently and those whose failure may cause serious consequences further consequences. Marine diesel engine was divided into the following functional systems: piston-crank exchange of the working medium, fuel supply, lubrication, cooling, starting, starting and reversing. Operating practice shows that the most common marine engine failure include damage to the injection system, the injectors, injection pumps, fuel system, speed controllers, lubrication system, timing mechanism, as well as the cooling system malfunctions. In this paper, examples of currently used diagnostic systems were described. In addition, the unconventional methods of diagnosing piston engines were presented. These are new, increasingly completely without disassembly and without any interference in the process of the internal combustion engine technical condition testing methods. Measurement systems computerization causes they are used with the simultaneous use of artificial intelligence and especially expert systems. These include, inter alia, vibration analysis, marine engine exhaust gas analysis, acoustic emission, endoscopy and quick photography in research diagnostics. Then infirmities cooling system were presented. The problem of development of methods of diagnosis and diagnostic system for marine diesel engine cooling system was formulated. It has been found that the developed diagnostic system would be a good complement to the existing electronic surveillance systems of the marine engine technical state.

In the article, changes in the properties of oils during operation were characterized. The main reason for this is the continuous aging process of the used oil caused by the interaction of oxygen contained in the air, which reacts relatively easily with hydrocarbons and the oxidation process is accelerated just by high temperature. Then the problem of microorganisms occurring in petroleum products and their effect on the properties of oils and the operation of the internal combustion engine was presented. The next part of the article presents effective microorganisms, i.e. what they are and how they work, in particular, their composition and appropriate development conditions. In addition, some of their specific applications were briefly described. In the next part of the article, the research methodology, applied oil samples with additives of effective microorganisms, both for fresh oil and used oil were described. In addition, the measuring test stand with instrumentation and measuring device was shown. The main part of the article contains the characteristics of dynamic viscosity as a function of temperature for fresh oil and used oil compared with oils with the addition of microorganisms in liquid form and ceramic tubes. The developed graphs enabled analysis of the effect of the addition of microorganisms on oil viscosity as ecological products.

In the article, base number as a parameter characterizing the washing and dispersing abilities of engine oil were characterized. Next, the influence of additives enriching engine oils on the natural environment was described. In the further part of the article, the research methodology, applied oil samples with additives of effective microorganisms and silver solution, both for fresh oil and used oil were presented. In addition, the measuring test stand with instrumentation and measuring device was shown . In the main part of the article base number value for fresh and used oil compared to oils with the addition of microorganisms and a solution of silver and colloidal silver were described. Next the analysis of the influence of these additives on the base number value was made. The article was completed conclusions.

In this paper, the existing methods to reduce the heat discharged by the engine were characterized and the efficiency of combustion piston engine was analysed, where it was shown the need and the potential for reducing the heat dissipated directly or indirectly to the surrounding atmosphere. The model of the engine cooling system for high coolant temperature developed through AMESim software was presented in this paper. The model of the cooling system was made based on test stand solution designed and built using original components and units diesel engine 4CT90. The simulation researches results of temperature course and pressure course were shown. In this paper was demonstrated that it is possible to maintain the assumed constant pressure of 0.3 MPa in the system and obtain it at the elevated liquid temperature leading to an increase in overall engine efficiency. These researches were carried out also on the experimental model stand, which confirmed the results obtained in simulation researches. Then 4CT90 engine test stand was described, where speed characteristics as a function of torque, power and specific fuel consumption and load characteristics as a function of the fractions of hydrocarbons, carbon monoxide and carbon dioxide, as well as specific and hourly fuel consumption were performed. Comparison of parameters and efficiency assessment of engine interacts with a traditional and pressure cooling system. The efficiency of the engine with the pressure and a traditional cooling system was evaluated.

The article presents the effect of the effective microorganisms and silver compounds addition on the flash point of new and used oil. The work describes environmentally friendly additives to engine oil. Next the ignition point of the engine oil were described. In the further part, the research stand and methodology were presented. In the main part of the article the flash point values for new and used oil compared to oils with the effective microorganisms and silver compounds addition were shown. New and used oil samples were mixed with effective microorganisms in the form of a liquid (2.5 ml and 5 ml) and ceramic tubes (3 pcs. and 6 pcs.). In addition, silver solution and silver compounds were mixed in the same amounts as the liquid effective microorganisms. In summary it was stated, that adding of the effective microorganisms to the fresh oil in liquid form causes the flash point to drop significantly. It follows that effective microorganisms in liquid form have a very negative effect on the properties of the oil. In the case of microorganisms in the form of ceramic tubes, which in this larger amount slightly increase this point compared to oil without additives. Regardless of the type of silver and its quantity, very low flash point values were obtained. For used oil the best results are obtained with the addition of microorganisms in liquid form. For the used oil the addition of silver compounds does not have the beneficial effect of restoring the original properties.