Genuine OEM Jaguar Timing Chain Tensioner, part number AJ814081. This vital engine component is responsible for maintaining the correct tension on the timing chain, which is crucial for synchronized camshaft and crankshaft rotation. Proper tension prevents chain slack, reducing wear and ensuring precise valve timing for optimal engine performance and longevity. Weighing approximately 0.095 kg, a genuine OEM tensioner provides the exact spring rate and hydraulic damping required for consistent chain tension, preventing costly engine damage and ensuring factory-specified reliability.