Hi all. I've been having a bit of grief with my 2020 Fit Sport. It's getting a bizarre squealing noise when the AC compressor is on, but only under certain circumstances and even then it is intermittent/requires the car to be driven a little bit before it occurs.

The car has always been taken care of, routine maintenance, etc. I had the fuel rail and injectors fail on me twice within 3 months a few years back (repairs covered by warranty ofc) and no other major issues have arisen since then. The car only has about 24720 miles on it.

The symptoms are:
In park AC on = no squeal
in park AC off = no squeal
In drive AC on (brake on) = squeal consistently, but only after having idled for 3 minutes in park, then driving 5 minutes, waiting in traffic for 5 minutes, and then observing the issue.
In drive AC off (brake on) = squeal stops
In neutral AC on = small bit of squeal when compressor kicks on, but after that no squeal or very minimal squeal
In neutral AC off = no squeal

Does anyone know what this could be? It sounds cyclical, so my suspicion is a belt of some kind, and the squeal is not very loud at all, nothing like what I've seen on YouTube of failing belts. It also sounds like it is coming more from the driver's side of the engine bay, near the wheel. It's also not affected by motion, other than aforementioned needing to be in drive.

Side note:
It was at the dealership for about 6 days over this issue already, and they came back saying they couldn't reproduce it. I tried to do it with them there when I went to pick the car up, but to no avail. Of course the day after I picked it up, the squealing started again. The bumper to bumper warranty is up in July so I'm really pressed to get this fixed ASAP and I'm kinda worried the dealership is dragging their feet on this. Would love to hear thoughts on this.

Here's a YouTube link to the sound in case it helps to diagnose: https://www.youtube.com/watch?v=i9yEQ818hlQ

 

Probably rust in the moving parts. I had similiar problem with this issue another car before. The solution is, try WD40 on the bearings, pulley, and the compressor clutch.