[Bmw43]

Hello all

I have had a sporadic humming/buzzing since I got my vehicle just over a year ago. The buzzing starts only when the vehicle has come to operating temperature. When I accelerate constantly at slow speed, this humming/buzzing occurs sporadically. Multiple visits to the dealer, but so far no success.

Is this normal? What could be the cause?

You can hear it in the video 4 times, first time at 2 seconds than again at 6 seconds and so on..
https://www.youtube.com/shorts/e0tAYGia2zc

[kjx]

Originally Posted by Bmw43

Hello all

I have had a sporadic humming/buzzing since I got my vehicle just over a year ago. The buzzing starts only when the vehicle has come to operating temperature. When I accelerate constantly at slow speed, this humming/buzzing occurs sporadically. I took my car to the shop and they replaced the transmission. The noise is now less, but still noticeable.

Is this normal? What could be the cause?

Transmission, differential, drive shafts, tires/wheels/alignment, belts, pumps? Could be anything. If you share a video maybe people can get a better sense of what you're experiencing.

That said, take it to the dealer. If you're not happy with the dealer you've gone to, take it to another one.

[Bmw43]

Originally Posted by kjx

Transmission, differential, drive shafts, tires/wheels/alignment, belts, pumps? Could be anything. If you share a video maybe people can get a better sense of what you're experiencing.

That said, take it to the dealer. If you're not happy with the dealer you've gone to, take it to another one.

I will try to make a video the next few days and hope you can hear it on it. This is my first M car and I can not really judge which sounds are normal and which are not.

[Bmw43]

Originally Posted by kjx

Transmission, differential, drive shafts, tires/wheels/alignment, belts, pumps? Could be anything. If you share a video maybe people can get a better sense of what you're experiencing.

That said, take it to the dealer. If you're not happy with the dealer you've gone to, take it to another one.

Here the link to the short clip:
https://www.youtube.com/shorts/e0tAYGia2zc

[kjx]

Originally Posted by Bmw43

Here the link to the short clip:
https://www.youtube.com/shorts/e0tAYGia2zc

Yeah, that's not normal. You should really have the dealer look at it again.

It almost seems like brakes getting auto-applied on a periodic basis at just the right intensity to cause a hum. Since it appeared like you had cruise control on, it's possible that was applying the brakes periodically? It could also be faulty sensors at the wheels telling the computer to periodically brake one or more wheels.

Is your alignment good? Are all your wheels and tires factory spec with the correct and matching air pressure on each axel?

I could easily be wrong as it's just a guess. You can troubleshoot more by varying things under your control.
- When the sound starts, what happens when you lightly apply the brakes?
- What happens if you turn the air conditioning system completely off?
- What happens if you let off the throttle? What about accelerating a bit more?
- If it's safe to do so, what happens if you shift the car into neutral when the noise starts?
- What happens if you upshift or downshift without varying speed?

[madpistol]

Are you sure it isn't your phone vibrating? It's happening very rhythmically. Is this only happening when you drive a constant speed, or does it also remain the same if you increase/decrease speed?

[Bmw43]

Originally Posted by madpistol

Are you sure it isn't your phone vibrating? It's happening very rhythmically. Is this only happening when you drive a constant speed, or does it also remain the same if you increase/decrease speed?

Has nothing to do with my phone. The sound can be clearly heard and I get a slight feedback through the steering wheel. It happens only in the range of 1300 - 1600 rpm. If I accelerate slowly and I pass through that range I can hear it for a second and if the car stays constantly in that range it appears sporadically.

[Bmw43]

Originally Posted by kjx

Yeah, that's not normal. You should really have the dealer look at it again.

It almost seems like brakes getting auto-applied on a periodic basis at just the right intensity to cause a hum. Since it appeared like you had cruise control on, it's possible that was applying the brakes periodically? It could also be faulty sensors at the wheels telling the computer to periodically brake one or more wheels.

Is your alignment good? Are all your wheels and tires factory spec with the correct and matching air pressure on each axel?

I could easily be wrong as it's just a guess. You can troubleshoot more by varying things under your control.
- When the sound starts, what happens when you lightly apply the brakes?
- What happens if you turn the air conditioning system completely off?
- What happens if you let off the throttle? What about accelerating a bit more?
- If it's safe to do so, what happens if you shift the car into neutral when the noise starts?
- What happens if you upshift or downshift without varying speed?

Thank you for your input. I'm pretty sure my alignment is fine as they checked it a few times. My car is also completely stock, so nothing has been changed. I'm also sure that it is not tire/brake related as it only appears when I accelerate constantly. The sound can be clearly heard and I get a slight feedback through the steering wheel. It happens only in the range of 1300 - 1600 rpm. If I accelerate slowly and I pass through that range I can hear it for a second and if the car stays constantly in that range it appears sporadically.

It's my first M-car and I can't really tell what is normal and what's not.

[misofly]

Originally Posted by Bmw43

Here the link to the short clip:
https://www.youtube.com/shorts/e0tAYGia2zc

Yep this is the exact sound I'm having with mine. Were you able to find what was causing it?

[Bmw43]

Originally Posted by misofly

Yep this is the exact sound I'm having with mine. Were you able to find what was causing it?

I've been to different dealers regarding this issue, but none of them were able to help. They tried different things and the noise is slightly less noticeable now but still there. At the end they told me this sound is normal and other G80s do it as well. The main reason I am looking to trade my car in and get a new one

[misofly]

Originally Posted by Bmw43

I've been to different dealers regarding this issue, but none of them were able to help. They tried different things and the noise is slightly less noticeable now but still there. At the end they told me this sound is normal and other G80s do it as well. The main reason I am looking to trade my car in and get a new one

Yeah this is one of those things where if I take it to the dealer, they won't be able to mirror the same issue or will just tell me it's normal. I had a mechanic friend of mine drive it for a day, and he wouldn't be concerned about it. We just have more sensitive ears

[ominousM4]

Just put it in D3 and you'll never be in the 1300-1600 RPM range.

[bri1042]

Originally Posted by misofly

Yeah this is one of those things where if I take it to the dealer, they won't be able to mirror the same issue or will just tell me it's normal. I had a mechanic friend of mine drive it for a day, and he wouldn't be concerned about it. We just have more sensitive ears

I stand by my theory that auto repair shops are loud and many mechanics don't realize that their hearing is compromised. I have gone on three drives with service center employees over the years so they could hear rattles that have annoyed me and they seriously could not hear what I could. The issue is either hearing loss or honesty loss...

Thus I've gotten pretty good with disassembling BMW interiors and applying felt tape.