Searching for the Causes of Abnormally Fast Degradation of Engine Oil in a Diesel Combustion Engine

Today, modern tribodiagnostics offers sophisticated analyzes of motor oils with fast and accurate results. However,Today, modern tribodiagnostics offers sophisticated analyzes of motor oils with fast and accurate results. However,finding the causes of some undesirable processes of engine oil degradation often requires long-term monitoring of the operatingfacility. In this case, it was a problem of diesel engine oil in the Citroёn Jumpy 2.0 HDi service minibus, which has been in useby the Department of Mechanical Engineering (Armed Forces Academy of General M. R. Štefanik, Demänová) for more than13 years. The fuel system (conditioners of injectors) on this vehicle has also been monitored for a long time in the period 2019-2021, an article about it was also published in the journal Science & Military (No. 2 / Vol. 14/2019). The cadets of theDeptartment of mechanical engineering Armed Forces Academy of General M. R. Štefanik, were also involved in the diagnosticprocess. In parallel with the fuel system, the quality of the engine oil was regularly monitored in the time interval 20.1.2020 -22.4.2021 at a start of 2185 km from the last oil change. During this monitoring, a very rapid degradation of engine oil wasfound in some parameters, which is atypical during normal vehicle operation. This article discusses the measured results andpossible causes of this adverse event.