Hey what's going on so I recently had my belt tensioner replaced in my 2012 buick lacrosse 2.4 eassist has 108,300miles but it still giving off a sound as if there is a bad pulley . I can't figure it out my self maybe some body here experience this before. Video is before the replacement but the sound is still there

Thank you. Joe

You Tube

 

I have heard that sound before , at least it sounds close.
The rubber insulation came out of the crankshaft pulley and it sounded just like an internal engine problem.
You may need a flashlite and mirror to confirm this.

One other thing you might try is to loosen the tension on the belt and rotate each pulley , you might find it then.

Another way to pin down the origin of the noise is to use a long thin stick and ,CAREFULLY, place one end of the stick on each component that is rotating and the other end near your ear. You will get one that is so loud , you can't miss it.
I don't like to suggest any procedure where someone can get injured and the thin stick works best , but please be careful when sticking anything into an area where there are moving parts. Some places will use a stethoscope just for this purpose.

I have a question that is puzzling me, If you had the tensioner replaced and you did not do it yourself, couldn't the other person have checked that before replacing a good part?