What is the purpose of an oil seal in a motor?

The purpose of an oil seal in a motor is primarily to keep the oil contained within the engine components while preventing external contaminants, like water and dirt, from entering the system. This sealing action is crucial for maintaining the integrity of the lubrication system. Proper lubrication is essential for reducing friction and wear between moving parts, which in turn helps in ensuring optimal performance and longevity of the engine.

By effectively sealing the oil passages, the oil seal helps maintain the correct oil pressure and ensures that the lubricating oil can do its job without being diluted or contaminated. This contributes significantly to the overall efficiency and reliability of the engine. The other choices, while related to engine operation, do not specifically address the core function of an oil seal in maintaining lubrication and protecting against external elements.