Engine Oil Stop Leak Helps Stop Minor Leaks in Main Bearing Sales, Pan, and Valve Cover Gaskets Helps Prevent Costly Repairs. Helps Stop Minor Leaks in Main Bearing Sales, Pan, and Valve Cover Gaskets Helps Prevent Costly Repairs. An effective combination of active solvents, additives and polymers stops leaks in seals and gaskets by restoring their size and elasticity. Designed for gasoline and diesel engines of passenger cars and small trucks with and without turbocharging, as well as for engines running on liquefied gas. Compatible with all oils.