* Worn piston rings. The piston rings are responsible for creating a seal between the piston and the cylinder wall, preventing oil from leaking into the combustion chamber. If the piston rings are worn, they may not be able to create a proper seal, allowing oil to leak into the combustion chamber and burn off, resulting in smoke coming out of the tailpipe.
* Damaged valve stem seals. The valve stem seals are responsible for preventing oil from leaking into the combustion chamber through the valve stems. If the valve stem seals are damaged, they may not be able to create a proper seal, allowing oil to leak into the combustion chamber and burn off, resulting in smoke coming out of the tailpipe.
* Leaking head gasket. The head gasket is responsible for sealing the cylinder head to the engine block, preventing oil and coolant from leaking into the combustion chamber. If the head gasket is leaking, it may allow oil to leak into the combustion chamber and burn off, resulting in smoke coming out of the tailpipe.
* PCV valve stuck closed. The PCV valve is responsible for regulating the flow of crankcase gases back into the intake manifold. If the PCV valve is stuck closed, it can cause a buildup of pressure in the crankcase, which can force oil past the piston rings and valve stem seals and into the combustion chamber, resulting in smoke coming out of the tailpipe.
To determine the exact cause of the oil and smoke coming out of the tailpipe, it is recommended to have the vehicle inspected by a qualified mechanic.
