During the operation of any combustion engine, its components wear due to friction. As the pistons move within the cylinders, both the pistons and, primarily, the piston rings, as well as the cylinder walls, undergo wear. Due to this wear, the piston rings increasingly fail to scrape oil from the cylinder walls, and the remaining oil is burned. In this way, most of the oil consumed by the engine enters the combustion chamber. Additionally, oil can enter the cylinder through worn valve seals and excessive clearance of the valve stem in its guide. The third pathway for oil to reach the combustion chambers is through a worn, leaky turbocharger. The wear of all these components is a natural process (just like human aging) and affects every engine. However, the problem is that in currently manufactured cars, this often becomes apparent after just a hundred thousand kilometers or sometimes even earlier, as in the case of the 1.8 and 2.0 TSI engines labeled EA888. Most engines experiencing excessive oil consumption are in need of a complete overhaul.
