What can result from worn valves?

Worn valves can lead to significant issues in engine performance and efficiency. When valves become worn, they can fail to create a proper seal when closed, resulting in burnt valve faces due to excessive heat and pressure. This degradation of the valve faces compromises the compression within the combustion chamber, leading to a loss of compression. As a consequence, the engine may not generate the necessary power for effective operation.

Additionally, worn valves can increase oil consumption, as oil may seep past the valves into the combustion chamber. This not only results in a decrease in overall performance but can also lead to higher emissions, as incomplete combustion occurs due to improper sealing.

The other options do not accurately reflect the consequences of worn valves. Enhanced engine performance and improved fuel efficiency are typically outcomes of properly functioning components rather than worn ones. Lower emission levels would also not be associated with worn valves; in fact, the opposite is likely to occur due to increased oil consumption and poor combustion characteristics. Therefore, understanding the impact of worn valves is crucial for maintaining engine health and performance.