What does the protective film of oil seal against to protect engine parts from corrosion?

The protective film of an oil seal is designed to shield engine components from oxygen and moisture in the air. These two elements are significant contributors to corrosion, which can lead to the deterioration of metal parts within the engine. When oxygen combines with moisture, it creates a corrosive environment that can facilitate rust and other forms of oxidation. By forming a barrier, the oil seal effectively minimizes direct exposure of engine components to these harmful elements, thus prolonging the lifespan and functionality of the engine parts.

In contrast, while heat, friction, dust, debris, and exhaust gases can have their own impacts on engine performance and maintenance, they are not the primary focuses of an oil seal's protective function against corrosion. The oil seal specifically targets the prevention of oxidation and corrosion resulting from environmental factors, highlighting the importance of this protective mechanism in maintaining engine health.