Weird Idle Noise "Chooch/Diesel" noise – 5VZ-FE

Hey everyone,
Looking for some input on a strange noise I’ve been getting at idle after installing a Magnuson TVS1320 supercharger on my 5VZ-FE. The truck is a 2002 Tacoma V6 5-speed manual. Runs great otherwise—no CEL, no performance issues, pulls hard—but there’s a consistent poof/chooching sound coming from the top of the motor at idle that’s got me scratching my head. in the vid below. You can actually hear it better without headphones. But either way works.
https://youtube.com/shorts/Cltxj8EpzRw?feature=share

What I’ve Tried:

• Supercharger Belt off = still makes noise
  
  
• Scoped with stethoscope = seems to come from Rear/rear top of engine
  
  
• Fresh oil change (5W-30, switching back to 10W-40 soon)

Other Notes:

• No change in drivability
  
  
• No misfires or codes
  
  
• Only occurs at 800rpm clears up at 1000+, goes away under throttle/load

Thank you for any input

 

Belt tensioner pulley, maybe.

 

I’d check all the pulleys and tensioners. Sounds like one of them may be loose.

 

Bust out your stethoscope, again