Subaru BRZ high pitched squeal/whine/buzz
 

Hello all,

I’m having an issue with my 2015 Subaru BRZ 79k miles and was wondering if anyone had a similar problem they resolved or could shed any light on what I should try next.

About 3 months ago I washed the car and when I started it I heard a very slight whine coming from the engine. It became louder with increased rpm. In the following three weeks it increased in intensity to what it is now. I looked everywhere and thought the sound was similar to an alternator bearing going bad. I replaced the alternator but the whine was exactly the same. I then thought it could be the accessory belt, but after replacing the sound was exactly the same. Does anyone have any ideas of what I should try next to diagnose and resolve the issue? Thank you!

Heres a link to a video I took this morning demonstrating the issue:
https://youtube.com/shorts/m1WtIs_RSPs?feature=share

The inner part of the AC compressor pulley is not spinning. These are clutched somehow. Wonder if it is smoked.

Remove the belt and spin stuff by hand. If any of the parts make the slightest noise, replace.


Also, try running it with the input connector of the alternator disconnected. ...the little one.

Take a long screwdriver and put it on the center bolt of every pulley. Listen for the one that sounds rough. I just upgraded to a set of raceseng pulleys because when i washed my engine bay I'm assuming the cleaner got into the bearing of my idler pulley and within a day or two the bearing started making noise.

Yup, ghetto stethoscope, I do it all the time. Just don't forget which side is pointy :bonk:

...or touch the moving parts


https://i.imgur.com/aFNw62A.gif

One of my buddies keeps sending me lathe video's like that and now I am tempted to get naked everytime I run the thing.

it doesn't normally spin unless the a/c is enabled, or hvac is set to 'auto', or 'defrost'.

still a potential spot though.


it almost sounds more like a rubbing noise. i know i've heard dozens of 90's GM's that sound exactly like that in the rougher neighborhoods, but never really learned what caused it!

It sounds like a power steering pump when the fluid is low.

modded '15 with a hydraulic steering assist? lol

Thanks for all the suggestions everyone! Going ti be working on the car tomorrow so will update then

Checked and the fluid is just below the max line

Funny enough this all started right after washing my car, I didn’t clean the engine bay though. I went ahead and did this after work today and all of the pulleys with center bolts that don't move didn’t sound/feel rough at all except for the tensioner pulley. Is this expected? Heres a closer video of it:
https://youtube.com/shorts/bGSG7JSbUJY?feature=share

Haha


https://c.tenor.com/N60q_8jMOlIAAAAd...-ben-stone.gif


That tensioner swing is perfectly normal. Healthy.