What causes blue smoke out of the exhaust?

Blue smoke from a vehicle's exhaust usually indicates that oil is leaking into the combustion chamber. Blue smoke can be a result of a number of underlying causes, including but not limited to:

- Worn or damaged piston rings

- Worn or damaged valve seals

- Faulty turbocharger seals (in turbocharged engines)

- High oil levels in the engine

- Engine overheating

- Faulty positive crankcase ventilation (PCV) valve