https://www.ebay.com/itm/302929176542

currently at $5,900 on ebay.

removed the belt tensioner, started the engine with no load on the coupler drive except the alternator and the noise is now gone. the tensioner bearing is not terrible by the spin test. I saw abscape suggested isolating the tensioner on another forum. Thank you! napa has the tensioner, pulley and au...

well it ended up to be a bad serpentine coupler pulley under the air conditioner. the bearing was rattling.

great repair by the local volvo dealer.