As seen in the video it's passenger side accessory drive belt area, definitely rpm dependent, but no driveability impact. At first I was afraid it was the sc but it sounds like a bad pulley maybe??

 

Some additional background: it just started this afternoon, one of the coldest days we have seen yet this year.
Car is 02 r53, 126k miles, had a WMW reduced sc pulley installed by previous owner about 40,000 miles ago.
New belt about 10,000 miles ago.
Just did a coolant and thermostat change about 3,000 miles ago.

 

try to spray some lubricant on the idler pulley to see if the sound changes. sounds like its coming from the belt area. hopefully its not your super charger

 

I forgot to mention that! I hosed the belt and pulleys with wd40 and made very little to no change in sound. So that's a bad sign.

 

ok next step try to get the belt off and start the car. (if it starts) see if the sound goes away. when the belt is off try to spin your accesories (a/c, sc pulley, alternator)to find the noise

 

5$ it's the alternator, here's mine:


The bearing in the back was eating itself and throwing metal particles all over the place. Best thing to do is to buy a mechanic's stethoscope and put it against various parts (While being careful about not touching the belt ). You'll be able to pinpoint the source, but this sounds awfully like mine.

 

Cool, whatever it is I hope makes it until the weekend

 

So it appears to be the tensioner pulley, it doesn't spin as freely as I would expect it to, and it sounds kind of "grindy" when spinning.

 

Oh and I also noticed the belt was swollen which I assume was from grease or oil being thrown on it from the axle boot that broke a while ago.
The guy at advance also noticed a portion of a rib was missing, so good thing I am replacing the belt before it completely disintegrated.

I assume a failing belt will also cause unusual noises.

 

And cost you big $$.....
when the belt fails...
the tensioner typically swings back with great force...taking a chunk out of the crank damper....could cost ya $750-1500 (damper $300-500, tensioner $75-200, belt $30, puller, and time, labor) to get it all fixed depending on where/what you use for parts!!

 

I have a WMW tensioner cable stop so no worries there, would still suck to get stranded.

New belt and spark plugs are installed, pulls like a banshee again! And I think the acceleration stumbling I had is gone.

I think I found the culprit of the noise, my heat shield had a loose bolt, but I still think the tensioner pulley needs replaced.