🔍 Key Concepts

• Behavior of trapped air in a closed liquid cooling system • How heat transfer is affected when metal surfaces are not fully wetted by coolant • Which effect would be considered the most serious/critical for engine safety and operation

💭 Think About

• Ask yourself: What happens to cooling efficiency if parts of the jacket are filled with air instead of water? • Which of the listed consequences could most directly lead to overheating or localized hot spots in the engine metal? • Consider which option is a direct physical/thermal effect and which are more long‑term chemical effects.

✅ Before You Answer

• Identify which choice is most directly related to loss of heat transfer from metal to coolant • Check which option would most likely create localized overheating (hot spots) in the cylinder jackets • Verify that the consequence you pick would logically follow from air collecting at high points in the cooling system where water flow is reduced or stopped.