What happens to the efficiency of the engine when the cooling system fails?

When a cooling system in an engine fails, the efficiency of the engine typically decreases. This is because a properly functioning cooling system is essential for regulating the engine's temperature; excessive heat build-up can lead to various complications.

In a scenario where the cooling system is compromised, the engine may overheat, which can result in several issues such as increased wear and tear on engine components, reduced lubricating properties of oil, and potential engine damage. As the engine operates at higher temperatures than designed, it can lead to a reduction in the combustion efficiency and an increase in fuel consumption. Additionally, an overheating engine may cause the engine control unit (ECU) to alter power output or throttle response in response to temperature changes, thus further diminishing overall efficiency.

Overall, a failing cooling system disrupts the balance necessary for optimal engine performance, leading to a decrease in efficiency.