Help! New engine sound - video included

A few days ago I noticed a new sound coming from my engine (2010 2.7l). It's a high pitched whine that increases with RPM. I've narrowed it down to the passenger side of the driveway engine, probably a bad pulley.

I suspect the alternator because it's original and I've got 207k miles. I took off the serpentine belt and played around with the pullys. Nothing obvious to me, but I haven't dealt with this before.

Video is from placing my phone on the air intake box and revving the engine from idle to 3k RPM.

VOLUME WARNING ⚠️



Has anyone heard this sound before and found a remedy?

Thanks for reading!

 

No video. Just saw your still waiting to upload.

 

You can't post videos here directly, you have to post them to a video sharing site and post the link here.

If you suspect it's an alternator you can unplug the connector at the alternator and see if the noise goes away.

 

I'll try that tomorrow, thanks!

 

When you had the belt off, did you start the engine and see if the noise was gone?

 

No I didn't try that. Had a local trusted mechanic look at it briefly (stopped by his shop unannounced) and he said it sounded like the alternator or nearby pully.
If its the alternator is the solution, I can do it myself. Otherwise, I'll be taking it back to the mechanic sometime next week.

 

Found this online before trying your suggestion:


I may just take it out the alternator and bring it to Autozone today to be tested

 

You don't want to unhook the big wire off the stud but on our trucks unplugging the connector with the engine off or running will simply remove power from the regulator and field coils essentially turning it off.
Now yes on some vehicles you don't want to do this as it could damage things.

Also if it's a bearing in the alternator failing unplugging it may not remove the noise.