[PVDO]

Hi all,
My G42 M240i xDrive (18k kms) started to make a weird high-pitched sound. It seems to only happen on warmer days or on longer drives, >30mins.
As far as i can figure it happens at various speeds from 20km/h up until 70km/h ish, but again only when warm.
Dealer checked it twice, found nothing. Problem is i cannot trigger it on purpose, some days it happens and some not.

Here is the video:
https://youtube.com/shorts/KvK9xvlh_KY?feature=shared

Anyone that experienced this aswell?
Getting kind of frustrated :-(
Thank you

[Navin_Johnson]

Originally Posted by PVDO

Hi all,
My G42 M240i xDrive (18k kms) started to make a weird high-pitched sound. It seems to only happen on warmer days or on longer drives, >30mins.
As far as i can figure it happens at various speeds from 20km/h up until 70km/h ish, but again only when warm.
Dealer checked it twice, found nothing. Problem is i cannot trigger it on purpose, some days it happens and some not.



Anyone that experienced this aswell?
Getting kind of frustrated :-(
Thank you

I would have guessed a rock lodged between a rotor and the dust shield, but if the dealer has checked twice, the rock would have been ground down and fallen out on its own by now.....
If it makes the sound at such a low speed, have a friend ride beside the car on a bicycle on either side to try to figure out which side it's coming from, and if it's louder in the front or back of the car. That would be something the dealer would never do. Then you could narrow it down a bit for the knowledge of the group here. The video helped, but it didn't help much either. More info is needed.

[PVDO]

Originally Posted by Navin_Johnson

I would have guessed a rock lodged between a rotor and the dust shield, but if the dealer has checked twice, the rock would have been ground down and fallen out on its own by now.....
If it makes the sound at such a low speed, have a friend ride beside the car on a bicycle on either side to try to figure out which side it's coming from, and if it's louder in the front or back of the car. That would be something the dealer would never do. Then you could narrow it down a bit for the knowledge of the group here. The video helped, but it didn't help much either. More info is needed.

Yes dealer also thought it was a rock between brake pad and rotor but they checked this twice already on all 4 wheels and claim not to find any.
I have the impression it comes from the front of the car rather than the back. I have to admit both times before it started i used launch control. Then that day and the days after the sound came/stayed.
Then i did not use it for about 2 months, used it again and the sound came back.

[Pentland]

Stones in the heat guard sound way worse than that.
If it’s happening some time after a cold start, it does point to something heating up, expanding and rubbing. Seizing calliper perhaps? Or rubbing on a disc?

I did note that it’s not a constant sound. It seems to stop momentarily when you turned the steering wheel.

[PVDO]

Originally Posted by Pentland

Stones in the heat guard sound way worse than that.
If it’s happening some time after a cold start, it does point to something heating up, expanding and rubbing. Seizing calliper perhaps? Or rubbing on a disc?

I did note that it’s not a constant sound. It seems to stop momentarily when you turned the steering wheel.

Exactly. It is not constant. Driving around town for example driving 4 streets, it can happen in 1 and not happen in 3 despite driving the same speeds. The frustrating part is i cannot trigger it on purpose. The times i went to the dealer it did not happen. So frustrating.

[cannockwolf]

I had that to but I just don't let the wife in the car now

[RockCrusher]

Originally Posted by PVDO

Hi all,
My G42 M240i xDrive (18k kms) started to make a weird high-pitched sound. It seems to only happen on warmer days or on longer drives, >30mins.
As far as i can figure it happens at various speeds from 20km/h up until 70km/h ish, but again only when warm.
Dealer checked it twice, found nothing. Problem is i cannot trigger it on purpose, some days it happens and some not.

Here is the video:
https://youtube.com/shorts/KvK9xvlh_KY?feature=shared

Anyone that experienced this aswell?
Getting kind of frustrated :-(
Thank you

Another car developed an intermittent noise that sounded much like the one in the clip. The source proved to be a bad idler roller bearing.

But the noise was present shortly after engine start and with the engine idling and the car stationary.

The same car also manifested a similar noise after I washed the car -- and due to the open engine cover (louvered) -- could not avoid getting water on the accessory drive system. Or if I left the car out in the rain or even parked over night on a hotel parking lot with a heavy fog.

In this case while I could hear the noise right after cold engine start after some idle time (<1 minute) the noise would go away as the accessory drive dried.

If the noise is never present with the car stationary see if you can affect the noise by applying the brake pedal some while maintaining a constant speed. If you can then suspicion has to be on the brakes. A pad is dragging perhaps.

[PVDO]

Originally Posted by RockCrusher

Another car developed an intermittent noise that sounded much like the one in the clip. The source proved to be a bad idler roller bearing.

But the noise was present shortly after engine start and with the engine idling and the car stationary.

The same car also manifested a similar noise after I washed the car — and due to the open engine cover (louvered) — could not avoid getting water on the accessory drive system. Or if I left the car out in the rain or even parked over night on a hotel parking lot with a heavy fog.

In this case while I could hear the noise right after cold engine start after some idle time (<1 minute) the noise would go away as the accessory drive dried.

If the noise is never present with the car stationary see if you can affect the noise by applying the brake pedal some while maintaining a constant speed. If you can then suspicion has to be on the brakes. A pad is dragging perhaps.

Can confirm it is never present when stationary, only while driving. Yesterday i figured out that when it happens and i make a steering movement it shortly disappears and then comes back when wheels are back straight (maintaining speed the entire process)….

[desertspotter]

I have similar noise twice, the first time louder, it was a stone between front brake and the shield. The second one a few weeks ago, more like yours, and also stone.

In my case, the second time the noise comes and goes intermitently but always at low speeds and sometimes disapear after turning.

Mi recomendation, move the car front and back and move the stering to the top while doing it. If it's a stone it will move and fall to the ground.