random squeal in the morning
 

I'm thinking maybe my belt tensioner might be starting to go?

I'll crank it up in the morning and once I put it in gear to start moving I can hear the serperntine belt squeal just like the old v--band setups used to. I simply blip the throttle and it shuts up for the rest of the day.

160k on an 01 3.0 x5. belt is new and has maybe 10k miles on it.

Best way to check is remove belt check all your rollers without belt installed. Just make sure they spin freely without noise.

Could be tensioner, could also be the starter

that would be the first time I'd ever heard a starter sound like that...and one that would wait until you put the car in gear and started driving before it started raising hell. normally, if they stay engaged you will know it immediately.

Mine squeals on a cold start (sometimes) and goes away after a second. Sometimes it doesn't squeal at all. I had the belts and tensioners checked, everything okay.

Sounds like Belt tensioners and idler bushing talking. Try this trick, pop out the dust covers and spritz the mounting bolt (the center of the pulley) with any general lubricant (WD-40 for example) and see if you belt drive noise stops ASAP. At times its just the pulley being dry. There are just bushings in there. NO bearing per say.
You can use a stethoscope to determine which one is your noise maker.

Alternatives:
Main drive belt itself walking on start up. Check for chaffing on edges.
Less likely:
Alternator bearings.
Water pump

Have you checked the belts for cracks on the inside grooves?

Have you had someone hold the brake and drop it in gear to see if you can pinpoint the location of the sound. Or, if only for grins, used a long extension to put against metal close to the pulleys and tensioners and the other end to your ear to see if they are noisy (not the squealing sound)?

:iagree::thumbup: