Alright guys.... I am experiencing very loud/annoying/embarrassing pulley/belt squeal out of my 2008 350z. 67k miles.

So about a month ago I replaced the smooth idler pulley because the bearing went bad in it. Everything was fine until about a week ago when the same exact noise came back. So we pulled both pulleys out and checked, the smooth one we replaced a month ago is/seems fine. The grooved pulley had just a little play, so we replaced it. But, noise is still there.

Belt looks fine to me... but if for some reason it isn't, could that cause a squeal like I am describing?

What should I check next?

Its so loud I can hear it in the cabin with the windows up, over my 3" single & TP setup. Very very embarrassing. I noticed tonight that after driving it for a little, the noise goes away when I put it in neutral.. right when I put it back into gear it comes back.

Air conditioning has been off whole time if that eliminates/proves anything.

Hopefully didn't forget any info..
Thanks in advance for the help.

 

It may be a cheap belt?
Is it squealing like a slipping belt or making a kind of chirping sound like an older chevy pickup?

 

It's just constantly squealing like a bad pulley bearing. The belt has been on for prob 15k miles and hasn't made any noises until recently.