I have recently been hearing a grumble from the top of my 1998 4.0L engine. Removed s/c and found:- oil puddle in the intake elbow and generally over the internals, light scoring to the casing inside, small area of missing finish to one of the vanes (but no scoring in this area), very slight but definite play in the rear bearings accompanied with a “click” as the vanes are moved sideways by hand. The oil drained from the plug was about 170ml - is this less than full capacity and would it account for the oil in the elbow etc? I assume there should be zero detectable play in the bearings? I haven’t separated the casing yet.
Am I right thinking replacement bearings and drive gears will give it a new lease of life?
Will try to uploads photos below.