Worn valve stem seals can increase oil consumption.

Worn valve stem seals can increase oil consumption.

• A. False
• B. It has no effect
• C. It reduces oil consumption
• D. True

Answer: (D)

Worn valve stem seals are meant to keep oil from leaking down the valve guides into the combustion chamber. When those seals wear, more oil can bypass into the cylinder and burn with the air-fuel mixture. That burning oil shows up as increased oil consumption and can cause blue smoke from the exhaust. So the statement is true: worn valve stem seals can increase oil consumption. If the seals are still good, oil intrusion is limited and consumption stays normal.

Worn valve stem seals are meant to keep oil from leaking down the valve guides into the combustion chamber. When those seals wear, more oil can bypass into the cylinder and burn with the air-fuel mixture. That burning oil shows up as increased oil consumption and can cause blue smoke from the exhaust. So the statement is true: worn valve stem seals can increase oil consumption. If the seals are still good, oil intrusion is limited and consumption stays normal.