Prelubrication in Engines

The lubrication in engines is provided by a pump which pressurizes the oil and forces it through all the moving surfaces of the engine.  At the time of starting, there is pressure in the lubrication oil. 

This can result in wear of the engine components during the starting process.  To prevent this, a special pump is used to pump the lubricating oil throughout the engine at the time of starting.  This pump is driven by a motor.  The engine will be permitted to started only after the lubricating oil has reached a certain value.