Crazy cycling seek on cold start then silence

[Tahomatom]

So when my wife starts her 2004 LX on cold mornings I get this cycling squeak. It disappears faster as the outside temps goes up and is only on start up. Doesn’t do it the rest of the day.

I had the idler pulley, drive belt tensioner, and fan clutch replaced and 2 days later it did it again. (Shop claims they were never able to recreate the noise) Tbelt don’t at 104k, Currently has 124k.

Seems to be coming from right behind the drivers firewall when inside the car but I just can find it in the minute it makes the noise after start up.
Can’t seem to get the audio to upload.
Ideas.??

 

[gregnash]

If you have a video of the sound upload to YouTube and then throw link here.
When was serpentine belt last done? Assuming when you had idler pulley and drive tensioner done?
Is it RPM related or no?
If you pop the hood when it is happening can you find or ensure it is coming from engine bay?

 

[Leandro]

Brake booster?

 

[Sargy]

I get it too sometimes. Normally happens during drastic humidity changes overnight. It could be my belt trapping moisture. I would say replace the belt but when the temps stabilize, I no longer have this issue