What are the causes of blue smoke from the engine?

[AliviaMarie]

This is caused by engine oil entering the internal combustion chamber, often due to the use of poor-quality oil or oil with an incorrect viscosity grade. Below are detailed explanations of common situations: Common scenarios: Use of substandard engine oil or prolonged use without replacement; Excessive back pressure in the turbocharger's oil return line. Poor piston ring sealing—inspect the condition of the cylinder liner, piston, and piston rings. Solutions: Replace with suitable engine oil, check for oil leaks in the turbocharger, including the turbocharger itself and the turbocharger oil return line. If the turbocharger oil return line is blocked, causing poor oil return, the oil may enter the intake manifold and burn in the combustion chamber, resulting in blue smoke.