Which of the following is a listed cause of high oil consumption?

Which of the following is a listed cause of high oil consumption?

• A. Failing or failed bearing
• B. Incorrect installation of piston rings
• C. External oil leakage
• D. Engine breather or vacuum pump breather

Answer: (A)

High oil consumption is often tied to parts that fail to keep oil out of places where it should not be burned or wasted. When a bearing is failing or worn, the clearance between the bearing and the journal increases. That extra clearance disrupts the precise oil control in the lubrication system, allowing more oil to escape into areas where it can be drawn into the combustion process or blown by blow-by into cylinders. Once oil enters the cylinders, it’s burned along with the fuel, showing up as higher oil consumption. External oil leakage, while it lowers the oil level, represents oil loss rather than oil being burned, so it isn’t counted as oil consumption. Incorrect installation of piston rings can cause oil burning too, but in this context it isn’t the listed listed cause being tested. Breather issues can also contribute to oil consumption in some cases, but the question’s documented list identifies bearing wear as the primary listed cause.

High oil consumption is often tied to parts that fail to keep oil out of places where it should not be burned or wasted. When a bearing is failing or worn, the clearance between the bearing and the journal increases. That extra clearance disrupts the precise oil control in the lubrication system, allowing more oil to escape into areas where it can be drawn into the combustion process or blown by blow-by into cylinders. Once oil enters the cylinders, it’s burned along with the fuel, showing up as higher oil consumption.

External oil leakage, while it lowers the oil level, represents oil loss rather than oil being burned, so it isn’t counted as oil consumption. Incorrect installation of piston rings can cause oil burning too, but in this context it isn’t the listed listed cause being tested. Breather issues can also contribute to oil consumption in some cases, but the question’s documented list identifies bearing wear as the primary listed cause.