Oil Sump (Oil Pan)

Sumps are pressed steel or cast aluminium. They have a drain plug and often an oil level sensor. Baffles inside reduce oil surge in corners and under braking. Some performance engines use a dry-sump system with a separate tank and extra pump to keep oil supply steady in hard cornering.

Oil drains back from the engine into the sump, where the oil pump picks it up again through a strainer.

A damaged sump or leaking drain plug can lose oil quickly. Use a new drain plug washer at each oil change. Scraping the sump on speed bumps can dent it and damage the oil pickup or level sensor.