🔍 Key Concepts

• Piston ring function in sealing combustion gases and controlling lube oil on the cylinder walls • Typical symptoms of poor compression or poor ring sealing in diesel engines • Which engine systems are directly affected by oil control vs. exhaust flow vs. crankshaft support

💭 Think About

• Ask yourself: If piston rings don’t seal properly, what happens to the oil on the cylinder walls during each stroke? • Which of the listed effects (oil use, temperature, exhaust back pressure, crankshaft movement) is most directly linked to a problem at the cylinder liner–piston interface? • Think about what would change inside the cylinder first, before it could affect any external systems.

✅ Before You Answer

• Identify which choice is directly related to cylinder sealing and oil control rather than to bearings or exhaust piping. • Eliminate options that mainly involve crankshaft support or exhaust gas flow, as those are influenced by other components. • Confirm in your mind how blow-by and poor ring sealing typically show up in engine operating logs or watch reports.