M14 x 1.5 x Yellow Bright Zinc Plated Steel Oil Drain PlugOil drain plugs drain the oil from the vehicle pan during an oil change. If there is a leak at the oil plug the gasket may be faulty and needs replacement. If the bolt or oil pan have been cross threaded the oil drain plug needs replacement. The gasket is a seal that keeps vehicle oil contained while it circulates from the oil pan to the engine block and back again.