This is a bout my wifes 02 supercharged xterra, it has over 160K miles

Newer modern stuff is not my forte, I am doing a retro rod road race thing on my 69 big block corvette so I do know how to spin a wrench but I am not too bashful to ask/beg for some insight and help from you guys savvy with the modern stuff.

For months the engine in the Xterra makes a whine, louder and climbs with engine RPM be it in or out gear.
If it was our vette I was trouble shooting I would look at things like the power steering pumps or alternator bearing, but the alt on the xterra was replaced not long ago,

I Googled the issue and it would seem most people point to a timing chain/worn out tensioner issue, but could be a supercharger bearing....

I will be paying a shop to fix whatever it is and will not pay the high rates the dealers demand but I want to go into the shop with some vision, how do I know for sure what is making the sound, lots of people say timing chain/worn out tensioner but is there a way to know for sure?

If that is what it is how long do these make noise before just giving up?

Thanks all!