Oil Pressure Relief Valve
A spring-loaded valve inside the oil pump that limits maximum engine oil pressure to prevent component damage.
The oil pressure relief valve is a safety mechanism integrated into the engine's oil pump. As engine RPM increases, the oil pump spins faster and pumps more oil, which naturally builds pressure. If the pressure becomes too high, it can rupture the oil filter, blow out seals, and put excessive drag on the engine.
The relief valve consists of a spring-loaded piston. When oil pressure reaches a preset maximum (typically between 50 and 80 PSI), the oil pushes the piston back against the spring, opening a bypass passage that routes excess oil back into the oil pan or pump inlet.
If the relief valve gets stuck open—often due to carbon deposits or debris—it will vent oil pressure constantly, resulting in dangerously low engine oil pressure at idle, which can cause severe engine wear. If it gets stuck closed, oil pressure will spike, potentially ballooning the oil filter and causing massive leaks.