My 1997 XJ sounds like something hitting fan on cold starts in winter. It's a ticking noise. On very cold mornings it will start but stall and need to be restarted. I've heard this could indicate a problem with rod bearings. I do know that the A/C clutch has a tendency to make noise engaging. This Jeep also sounds like an old Mercedes diesel on warm starts where the synthetic oil is not hot, but not cold. It never made the Mercedes diesel sound until I put in some synthetic. On Shell T5 10w-30 synthetic blend it was always quiet. Anyone care to suggest if this noise is truly indicative of rod bearings or other lower end problems? Running the same oil, my 01 XJ is quiet as a church mouse, but it's had synthetic all its life.... 97 XJ has an unknown history. I've had the 97 for the past 40,000 miles and the 01 for the past 307,000 miles...