Examination of engine cylinder-piston group damages

Abstract

Abstract Results of investigations of engine cylinder-piston group (CPG) damages and causes of their occurrence are given. The object of the study is the KIA Ceed engine, which came for examination due to a significant decrease in power, increased consumption of motor oil, violation of the dynamics of the car. The analysis of the technical condition of the disassembled engine showed that the parts of the crank mechanism and the cylinder head have no operational damages. Serious damages were detected only in the cylinder-piston group of the engine: abrasive wear of the working surfaces of cylinders, pistons and compression rings, coking of oil removal rings, deposits on the surfaces of all pistons of the engine. According to the results of the studies, the cause of loss of efficiency by the engine is the destruction of the ceramic catalyst, the products of which in the form of ground powdered substance enter the cylinders together with the exhaust gases. This occurs at the moment of simultaneous opening of exhaust valves of two cylinders having different exhaust gas pressure. A small amount thereof, together with the catalyst breakage products, penetrates the lower pressure cylinder through the manifold. A study of the substance of deposits on the pistons of the engine and the destruction products of the elements of the ceramic catalyst (cordierite Al4Mg2O16Si5), carried out on the powder diffractometer BRUKER AXS, showed the identity of their diffraction composition. This indicates that damage to the parts of the CPG and loss of performance by the engine is caused by destruction of the ceramic catalyst.