A strange squealing noise between 1.2/1.5k Rpm

[Fabraam]

Hello everyone, I'm having a strange squealing noise coming from the drive belt side, in between 1.2/1.5k rpm. I have tried to remove the belt and start the engine, no noise there. So as a starting point I tried to replace the belt tensioner and idler pulley. Unfortunately after re fitting all back, this stupid noise was still there. I have tried to listen with a screwdrive on top and side of the alternator and from the center of the water pump, but I cannot hear anything on either of them, so I just ordered a stethoscope to make sure i'm 100% positive.
So my question here is have any of you heard this noise and found where was coming from? Link below is the video of the noise.

https://youtube.com/shorts/AXYjJRBfuIA?si=3AD0xlj9ZKkiV-1r

Thank you everyone for the help.

 

[XR650R]

Doesn't sound like a squeaking belt. Sounds more like an intake noise.

 

[madhatter]

possibly the timing belt tensioner. sounds like metal on metal.

 

[FiSt200]

Most of the time, that sound is associated with a bad pulley. Since you already changed the tensioner and idler pulley, it could be either of the other pulleys. Using a stethoscope is not so accurate on some of these pulleys, as the only place you have to make contact is oscillating, causing vibration - this will cause noises in the earpieces that could mask the one that you want to hear.

Try using a rubber pipe/hose. A garden hose will work fine. Place one end to your ear and hold the other end close to each pulley (do not make physical contact). This will give you a general idea of where it is coming from, and then you can investigate further from there.

Seeing that it is inexpensive, try this as one of the first things. While the engine is running, gently press a bar of soap or a candle against the inside of the belt (groove side). If the noise goes away, change your belt. Highly unlikely but worth a shot nonetheless.

If it were an intake noise, there would be a distinct change in volume/tone.

Just my thoughts.

 

[Fabraam]

possibly the timing belt tensioner. sounds like metal on metal.

Withough the drive belt on, the noise is not there, while the engine is running, so timing belt or tentioner is out of the equation.