Hello everyone,
Have not been here in a while. While starting my wife's 1997 Grand Cherokee the other morning, I noticed it was louder than usual. Almost sounded like a "quiet diesel" engine. It idles and drives normal. There is no lack of power etc. The noise is new and does not sound good, almost like bad bearings in a pulley. I checked the obvious first. The belt is fine, good shape and correct tension. Power steering fluid is full and clean {I had a Buick make a similar noise and it was the power steering pump}. I also checked the air intake for blockage, thinking it was starved for air. Any suggestions or kicks in the right direction would be appreciated. I have included a video link to Youtube of the engine running. Hope that helps. It is a v6 with 110,000 miles. Here is the link to the video. Bob.

http://www.youtube.com/watch?v=TS0JIvA86DU

Sounds Like a bad bearing in a pully. I had something similar in the pulley that is spring loaded and puts the tension on the serpentine belt. Release the belt and spin that pully by hand and if that is not it, you can hand spin all the rest. Power steering, ac, water pump, alt. etc. If that does not find the noise, I am stumped.

Thanks for the suggestion, that's what I need to do next.