🔍 Key Concepts

• Relationship between coolant system and lubricating oil system in a diesel engine • How coolant can physically enter the crankcase or oil spaces • Typical failures of injectors, oil system, and engine structure

💭 Think About

• Which of these choices actually puts coolant in direct contact with the lubricating oil spaces? • Does changing pressure alone (high or low) create a new path for coolant to enter the oil, or must there be some kind of leak path or damage? • Which component, if damaged, would allow coolant from water jackets to pass into the combustion space or crankcase?

✅ Before You Answer

• Identify which options involve a physical breach between the coolant passages and the lubricating oil areas • Rule out options that only affect pressure but do not create a path for fluids to mix • Think about the location of water jackets in relation to the cylinder head and liner versus the fuel system and lube oil system