The oil pan gasket seals the joint between the engine and the oil pan from which the oil is pumped into the spots that need lubricating. Replacing the gasket requires draining the oil and removing the oil pan. In the case of certain car models this procedure requires removing many other elements or even lifting the engine. In order for a new gasket to function properly, the joint between the engine and the pan must be cleaned thoroughly and all the bolts must be tightened properly with the right torque (using a torque wrench).
What is the sump?
The sump is located at the bottom of the engine. It is a reservoir in which the oil pumped trough the engine's lubrication system pools. The oil is sucked in by the oil pump strainer. The connection between the sump and the engine block must be tight. To this effect, a gasket is applied, which prevents oil from leaking out.
When should the sump gasket be replaced?
Given the different conditions in which the gasket operates, it obviously wears out, causing oil to ooze out, staining the sump and the bottom of the engine. If this is the case, the gasket must be replaced.
How is the sump gasket replaced?
First, the oil must be drained. To this effect the drain plug must be removed from the sump. Next, the bolts holding the sump to the engine must be removed. After removing, the sump should be cleaned of old gasket leftovers and checked for any mounting surface deformations and other damages. Then a new gasket is fitted. In some car types, the role of the gasket plays silicone resistant to high temperatures, which is evenly applied on the contact surface between the sump and the engine block. Subsequently, the sump is fitted back into place and screwed to the engine.
What else to keep in mind?
The bolts should be properly tightened in order to ensure that the sump is pressed against the engine with the right force, and that it does not become deformed in the process. If silicone is used instead of a gasket, you should wait the required time for it to harden before you fill the engine with oil and start it to check it for any leaks.