Best to remove the serpentine belt and turn pulleys by hand. Water pump, alternator, tensioner, power steering.

I suspect the belt tensioner. Did you buy a spring type?

 

The noise is basically unchanged after I replaced the tensioner (and pulley). It is OEM (hydraulic damper).

I did the turn by hand trick. It’s difficult to translate the feel at low speed to the noise at high speed.


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Some people will remove the belt and operate the engine just for a moment to see if the noise goes away.


You can try finding an auto parts store that will let you handle/inspect a new water pump. Feel/observe how the pulley spins and compare that to your water pump. Also check for any play in any of the component pullies.

 

I think that is water pump's noise. I got the same and hesitate at least 3 months before replace it.

 

You should be able to tell what bearing is bad by removing the belt and turning each pulley. It could be your alternator also.
If you have a stethoscope or a long screwdriver , try touching near each pulley while the engine is running. The noise should be easy to detect.

 

My water pump made a similar noise when it was going bad. I could clearly hear it from inside the cabin. I took the serpentine belt off and spun it quickly by hand. Even if it's not as loud as when the engine is spinning, you should still be able to hear if it's quiet or if there's some grinding. Especially if you compare it to the other parts and it sounds louder.

 

With that many miles, I would be replacing the water pump and alternator as preventive maintenance.