Reliability assessment of a truck engine based on measurements of combustion chamber tightness

The article shows an analysis of the reliability of a compression-ignition engine used in a medium duty truck. The criterion for the reliability assessment was the decrease in combustion chamber tightness. The analysis was based on the results of compression pressure tests and leak-down tests conducted during a long-term operation of 5 trucks. Experimental survival functions and then continuous reliability functions, fitted to the empirical ones, were determined along with the failure rate functions.