Just for the benefit of anyone else with this issue I have an 06 4.0 with only 27K miles and I had the same problem. I don't have a distributor however it is actually a cam synchronizer, but it is an identical problem. The bushings in the housing are bad and I would get a terrible screeching for about a minute or two when the engine was cold and would first start up. If you hear this I wouldn't wait to long as the gears on my drive were wearing very quickly and could eventually start slipping or hurt the camshaft. I just couldn't believe I would have this issue with such a low mileage engine.