The oil sump plug is an essential component in a car's engine system. It is typically located at the bottom of the engine oil pan. Its primary function is to provide a secure seal and prevent oil leaks from the oil pan, which houses the engine's oil reservoir. Without a properly functioning oil sump plug, the engine would lose valuable oil, leading to insufficient lubrication and potential damage to the engine parts.

Furthermore, the oil sump plug has another crucial role - facilitating routine oil changes. Mechanics or vehicle owners can remove the plug to drain the old, contaminated oil from the engine without the need to dismantle the entire oil pan. Once the oil is drained, a new filter can be installed, and fresh oil can be added. This process helps to remove debris and maintain the health of the engine, ensuring optimal performance and longevity.