Wtf is this scary rattle engine noise

[ddnww]

Just started yesterday. Did this for about 30 min. Now it settled to a small rattle but still rattling. Please tell me otta just a pulley or something. 07 v6.

 

[djkurious]

First, Happy New Year!
Secondly, definitely sounds like a pulley.
Remove the belt and spin each pulley and observe the sounds.

 

[riceandpho]

the pulley next to the power steering is bad. good time to replace both idle pulleys, the one next to the alternator is the same.
the one by the air conditioning is different part number and you can change it too.
some also swap out the auto tensioner too.

i used the dayco brand pulley and belt with no problems. havent switched out the tensioner and im at 170k

 

[ddnww]

Got it. Thanks guys. It was a idler pulley. That was the scariest sound of my life.