Whistle noise after warm up

[postmortem]

After driving for approximately 20 minutes, I start hearing a whistling sound coming from behind the steering wheel. I believe I can also hear it from outside, near the front left side of the car. The sound is present even when the car is parked and idling (as shown in the video). If I rev the engine while parked, the noise becomes slightly louder. Here’s a video for more details:

Is this normal?

2017 CX5 Grand Select 109k miles.

 

[stickerbush]

Not normal, sounds like ignition interference with the audio system but I presume you have the audio sound turned off or muted. Try opening the hood and listening to see if you can better isolate the source. For example, front of engine, back of engine, etc.

 

[postmortem]

Not normal, sounds like ignition interference with the audio system but I presume you have the audio sound turned off or muted. Try opening the hood and listening to see if you can better isolate the source. For example, front of engine, back of engine, etc.

I think I can hear it on the driver’s (US version) side of the engine with the hood open, the engine sound itself makes it a bit harder to hear. I can also hear it if i put my ear close to the left front wheel.

 

[postmortem]

Update: Mazda says a new transmission and rear differential are needed. 15k in total repairs.

 

[elementCX5]

Could be a "we can't find the issue and proper diagnosis in time so we're giving you the take it somewhere else" price. I would get a 2nd opinion for sure without telling them anything about what the Mazda dealer said. If they say the same it might be time to trade it in.
I also wonder how the trans fluid looks? Low? Might not even be coming from the transmission, but I'm just throwing ideas out there.
Revving in neutral doesn't spin the rear diff so I don't think that's what's causing the noise unless it was tested as bad also. Just seems odd.

 

[postmortem]

Could be a "we can't find the issue and proper diagnosis in time so we're giving you the take it somewhere else" price. I would get a 2nd opinion for sure without telling them anything about what the Mazda dealer said. If they say the same it might be time to trade it in.
I also wonder how the trans fluid looks? Low? Might not even be coming from the transmission, but I'm just throwing ideas out there.
Revving in neutral doesn't spin the rear diff so I don't think that's what's causing the noise unless it was tested as bad also. Just seems odd.

I took it to Mazda and just told them about the constant whistle-like noise coming from the front. They did an inspection and found a couple of issues besides the transmission. They even recorded a video with everything they found. In the video, they shake the rear differential, and it was making a weird clanking sound. They told me the bearings inside were broken. They also asked me if I heard a noise coming from the rear while driving, then I told them yes. I heard a weird noise from the rear while driving, but I was planning on telling them about it after the inspection.

They quoted $7,244 for a transmission replacement and $4,877 for rear differential repair/replacement, among other things like belt tensioner and sway bars replacement. In total, if I chose to do everything, the quote is $15,944. I paid $13k for this vehicle...

The only thing that's keeping me from going insane is that I chose to pay for a 3-month warranty extension that expires at the end of next month. Today, I'll be taking the vehicle to one of their "in-network" facilities to see if they can cover the repairs.

 

[N7turbo]

I'm pretty sure a broken differential would interfere with normal operation.

Do you get any clunking noises from the rear when turning?

And the price on that transmission replacement is wild.

This is crazy on a 2017, IMO.

What seems more likely is that the sound is engine related because the transmission does not spin while in park (at least not the gears or the output shaft). So what could explain the wild repair prices? A dealer that wants someone to go away, perhaps...

 

[postmortem]

I'm pretty sure a broken differential would interfere with normal operation.

Do you get any clunking noises from the rear when turning?

And the price on that transmission replacement is wild.

This is crazy on a 2017, IMO.

What seems more likely is that the sound is engine related because the transmission does not spin while in park. So what could explain the wild repair prices? A dealer that wants someone to go away, perhaps...

Maybe, I left it at another shop today. Let's see what they say