Not changing the oil would certainly lead to noisey valves but putting in new oil wouldn't get rid of the problem. Sort of the barn door and horse situation. Although there have been some reports of noisey 850 valves on startup that others have said is sort of typical for the engines. CV joints will wear out but usually they get noisey when you steer the car. Check the boots for tears and grease leakage. Have only seen one report of axle failure on the 'board and this involved what looked like an axle actually breaking apart suddenly! Very nasty situation.