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

 

[nickswhip24]

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

so...what happened...did they cover you on the repairs?

 

[postmortem]

The other ship charged me 5000k to replace the rear differential with a brand new one from mazda. My warranty covered 2800. I paid for the rest.

 

[nickswhip24]

The other ship charged me 5000k to replace the rear differential with a brand new one from mazda. My warranty covered 2800. I paid for the rest.

so,just rear,transmission was ok? maybe i will need to get that extended warranty before oem one runs out,thanks

 

[postmortem]

so,just rear,transmission was ok? maybe i will need to get that extended warranty before oem one runs out,thanks

Rear differential was broken I got a new one installed.

All noise from the rear is gone and the car runs much better. I still hear a faint whistle noise from the front. I just chose to ignored it, the car runs perfect anyways. I did a transmission fluid change just in case.

 

[nickswhip24]

Rear differential was broken I got a new one installed.

All noise from the rear is gone and the car runs much better. I still hear a faint whistle noise from the front. I just chose to ignored it, the car runs perfect anyways. I did a transmission fluid change just in case.

nice.i am new to mazda so learning what i can from this site-thank you...glad you made out

 

[RedBaron]

The other ship charged me 5000k to replace the rear differential with a brand new one

Holy crap! $5000 to replace a diff? Ouch.

 

[postmortem]

Holy crap! $5000 to replace a diff? Ouch.

Oh yeah. That hurt, I had like 2 months with the car too. At least I got a brand new one, directly from mazda.

 

[postmortem]

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

Not exactly. The way they diagnosed the bad rear differential was by lifting the car high enough for all of us to stand underneath it, with someone inside the vehicle. Once the car was in the air, the person inside accelerated so the wheels began spinning. As soon as that happened, the rear differential started making noise and shaking.

We were also able to physically move the axle connected to the rear differential by hand, which confirmed the internal bearings were damaged. There should be no play there. I tried the same test with the new differential, and it’s completely solid.

I've attached a video of the Mazda technician shaking the rear differential of my CX5, where he diagnosed it as damaged. That thing should be solid, there should be no play.

You can get under the car and do it yourself, you don't need to lift it. At least you don't have to lift to verify is there is any shaking.

 

[madar]

Whistling trans is a common issue on this sight. Appears that a bearing goes bad in the trans. I had a trans replaced on my '14 CX5 back in the day for this issue under warranty.

 

[postmortem]

Whistling trans is a common issue on this sight. Appears that a bearing goes bad in the trans. I had a trans replaced on my '14 CX5 back in the day for this issue under warranty.

Yeah, at Mazda they told me the whistle was coming from the trans and that they recommend a replacement to get rid of it. That would be 7500 USD. Yeah, no.

I barely notice it anymore and the car runs fine, there's another user here with the same whistle, he ran it from 20k miles and still has no issues and the trans fluid looks good to this day. I did a transmission fluid drain and fill just in case.

I'll keep the maintenance by the book and drive this thing to the ground.

 

[madar]

Yeah, at Mazda they told me the whistle was coming from the trans and that they recommend a replacement to get rid of it. That would be 7500 USD. Yeah, no.

I barely notice it anymore and the car runs fine, there's another user here with the same whistle, he ran it from 20k miles and still has no issues and the trans fluid looks good to this day. I did a transmission fluid drain and fill just in case.

I'll keep the maintenance by the book and drive this thing to the ground.

Have you looked into any independent shops that could address this issue?

 

[postmortem]

Have you looked into any independent shops that could address this issue?

I took the car to two additional shops after visiting Mazda. Both confirmed they could not find any issues with the transmission. One of the shops stated that the whistling noise is considered normal operating sound. Based on this, the warranty will not approve a transmission replacement since no fault has been identified.