Genuine OEM Jaguar Valve Spring, part number AJ814310. This essential engine component is responsible for closing the engine valves after they have been opened by the camshaft, ensuring proper sealing of the combustion chamber. It is located within the cylinder head, surrounding the valve stem. Using a genuine OEM valve spring guarantees the correct spring rate, material fatigue resistance, and precise dimensions for reliable valve operation and long engine life, preventing premature wear and potential engine damage.