🔍 Key Concepts

• Relationship between cooling water, lube oil, and fuel systems on a diesel engine • How water can physically reach a single cylinder and also the crankcase when the engine is idle • Difference between internal leaks (liners, coolers) and external sources like condensation

💭 Think About

• Ask yourself: If only one cylinder shows water, what engine part is unique to that cylinder and also connects down toward the crankcase? • Consider how a leak in each listed system (fuel, liner, lube oil cooler, condensation) would move water—could it reasonably end up in both that cylinder AND the crankcase on an idle engine? • Think about which of the options would more likely affect ALL cylinders or the whole engine, rather than just one cylinder.

✅ Before You Answer

• Verify which system actually carries water as a normal working fluid and where that water is routed in the engine. • Check whether condensation would realistically accumulate enough in ONE cylinder and also reach the crankcase on an idle engine. • Confirm which component, if failed, would allow water to pass into a specific cylinder and then drain down past the piston rings into the crankcase.