Your vehicle needs oil to lubricate, cool and clean its engine. The oil sump is located at the bottom of the crankcase and is where the oil collects and is stored when your vehicle is parked and the engine isn’t running. It’s also where the oil pump is located. Oil sumps usually are made of thin steel or plastic, come in various sizes depending on the make and model or your vehicle, and are between 14 and 17 centimeters deep. A sump plug can be removed to allow old oil to flow out during an oil change. Oil sumps can rust out over time or get damaged by speed bumps or kerbs. Puddles of oil under your vehicle are a sure sign of a failing oil sump.