Few possible causes are as following:
1. Worn Oil Rings: Piston rings are responsible for creating a seal between the piston and the cylinder wall, preventing oil from entering the combustion chamber. Worn or damaged oil rings can allow oil to leak into the combustion chamber, resulting in blue smoke.
2. Cylinder Head Gasket Failure: A faulty cylinder head gasket can also lead to blue smoke. When the gasket fails, it can create a path for oil to leak from the oil passages into the combustion chamber.
3. Worn Valve Stem Seals: The valve stem seals form a seal around the valve stems to prevent oil from entering the combustion chamber. Worn or damaged valve stem seals can result in oil entering the combustion chamber, causing blue smoke.
4. Turbocharger/ Supercharger Failure: If a vehicle is equipped with a turbocharger or supercharger, these components can fail and force oil into the combustion chamber, resulting in blue smoke.
5. Engine Blow-by: In older engines, excessive "blow-by" can occur, where pressure and gases from combustion can leak past piston rings and into the crankcase. This can lead to high oil consumption and can also cause blue smoke.
It is important to note that blue smoke from the exhaust is often accompanied by other symptoms, such as oil consumption, engine knocking, or reduced performance. If you observe blue smoke from your exhaust, it is recommended to have your vehicle inspected by a qualified automotive technician as soon as possible to identify and resolve the underlying issue.
