How to adjust valve lash 4.0 1997 Jaguar XJ6?

To adjust the valve lash on a 1997 Jaguar XJ6 with a 4.0L engine, first ensure the engine is cold. Remove the valve cover to access the rocker arms. Using a feeler gauge, measure the gap between the rocker arm and the valve stem; it should be set to the manufacturer's specifications (typically around 0.010 inches for intake and 0.012 inches for exhaust). If adjustments are needed, use an appropriate wrench to turn the adjusting screw on the rocker arm until the desired clearance is achieved, then recheck with the feeler gauge before reassembling the valve cover.