'01 Impala 3.8L please heeeeeeellllllppppp me

I have a 2001 Impala 3.8L with 93,000 miles on it.
When the car warms up, it starts to make a loud screeching sound.
It starts out light but then gets very strong. It sounds like something spinning.
The problem started about 3 months ago and hasn't changed. It doesn't effect the temperature or the driveability of the car.
I've changed the belt, belt tensioner, pcv valve assembly, o-rings, and tested for vacuum leaks with no resolve.
One guy told me it might be the "crank pulley" which I've never heard of. Another mechanic told me it might be the torque convertor.
I don't want to waste any more money on this problem. I want to fix it right this time. It's embarrassing driving down the street!
If anyone can give me advise or if you had the same issue, I would greatly appreciate the help.

Where is it coming from? Does it do it with the belt off, not enough info to really help here without checking this on site. Idling, racing the engine, driving, hot cold???

Where is it coming from? Does it do it with the belt off, not enough info to really help here without checking this on site. Idling, racing the engine, driving, hot cold???
The sounds comes somewhere from the middle of the engine.
Yes, it does it with the belt off. All components of the belt were checked.
It does it when the car warms up after driving for about 10 minutes. The sound starts out minor and gradually gets very loud.
It makes the sound while the car is idle and while I'm driving.

I'd be looking for a minor vacuum leak here, particulary around the map/pcv, based on your description. Noises are virtually impossible to accurately diagnose in this environment. Why not get a pro to listen to this?

Could possibly be a cracked plenum or intake gasket leak. Both will get worse as the engine warms. May be able to spray some water over the intake while running and see if it sucks some water in making the engine rough or stall.

I had a crazy noise like that on my 01 but a fellow on here told me to make sure the O ring on the PCV valve was there and I had threw it away when I changed it didnt think there should be one there any way 1.00 or so later that was it no more noise.

I had a similiar problem with my 01 impala, never found out what that terrible noise was. However after listening to in occur over a period of time my a/c went out and now it doesn't blow any air out and the car doesn't make the sound anymore. Look maybe for a possible link between the two.

I have a 2000 Impala and I had the same sound and turned out the be the A/C pump bearing. It did it for a while but eventually stopped on it's own. He said that if I want A/C that it would have to be replaced however didn't bother cause it's a pretty penny to do so, suffering it out!

Hope this helps.

sounds like an intake vac. leak take a can of wd40 (not water) and spray around the intake the engine should rev up if there is a leak. if not did you put belt dressing on your belts or some sort of lube, because if you did the a/c clutch material will prematurely wear out and the clutch will go bad sometimes making a funny noise cheaper replacing clutch than whole compressor. Also take a long socket extension and I mean long and put it around the motor in various spots to pin point where the sound is definately coming from & the other end squeese your hand around and put hand around and then put your ear to it to listen(watch your hair or clothing when doing this). You will notice the difference in the sound resonating through the socket extension(poor mans stethescope). Also check power steering fluid might be low. Good Luck hope I was helpfull