🔍 Key Concepts

• Effects of low engine temperature on combustion quality in diesel engines • Relationship between fuel atomization, ignition lag, and cylinder temperature • How lube oil viscosity and misfiring are affected by colder-than-normal operation

💭 Think About

• Think about what happens to fuel droplets when they are injected into a cylinder that is too cold. Do they burn more easily or less easily? • If the engine and cooling water are colder than normal, what happens to combustion stability in each cylinder? More smooth firing, or more irregular firing? • Consider whether running cooler would actually thin the lube oil, or make it thicker, and how that relates to the answer choices.

✅ Before You Answer

• Verify which of the listed effects is most directly related to poor combustion in a cold cylinder. • Check your understanding of how temperature affects lube oil viscosity: does lower temperature reduce or increase viscosity? • Ask yourself which option reflects a negative consequence typically warned about when operating a diesel at light load and low temperatures.