[Bagelfast]

This buzzing, humming sound from the dash happens on and off at times.
It happens when the car is warm and only can be heard at idle when very quiet.

Ac off, radio off, all windows up at idle, I hear the humming sound from the dash, its pretty annoying.

I lightly rev, and the sound is directly tied to the revs/rpm, and at 1,000 rpm the humming sound shuts off and goes away!

2010 E90 335i N54 with 28k miles.

Anyone have any idea what it can be?
To be more clear on the sound, since I cant capture it on video.. Its on a on/off humming/buz.. BUZZ buzz BUZZ buzz.. And when I rev lightly it gets faster, and at 1k rpm it disappears.

[ForzaLazio9]

i have the same thing and am curious what that is, maybe the hard drive for the idrive, mine sounds like it is right under my idrive

[Bagelfast]

Originally Posted by ForzaLazio9

i have the same thing and am curious what that is, maybe the hard drive for the idrive, mine sounds like it is right under my idrive

I ruled out electronics from the dash, as for me, its rpm dependent.

[ForzaLazio9]

im a bit nal about noises like this, drives me nutts ill turn off all music, heat etcc... and listen to the noise and wonder wtf is this hahhahah

[Dark_Knight_335]

Yep same thing here 2011 N55

[str8flush]

Same issue with my 2010 e92 335i. The buzzing noise has something to do with the light switch. Put ur ear right up against the radio/centre console, then try turning your lowbeams on and the buzzing noise will appear. This happens when the car is both on and off as long as ur lowbeams are on. If you keep the switch on "auto" or "fully on", the buzzing noise continues. However, if you turn the light switch completely off, the buzzing noise will go away. I have an appointment with bmw on monday morning. Will see what they say. I think it might have something to do with the radio or headlights. Faulty wires maybe...dunno?

[Dark_Knight_335]

I'm sure I don't have a leg to stand on - after all, i have a full LED conversion in the entire car.

[Bagelfast]

Originally Posted by petr_rsti

Same issue with my 2010 e92 335i. The buzzing noise has something to do with the light switch. Put ur ear right up against the radio/centre console, then try turning your lowbeams on and the buzzing noise will appear. This happens when the car is both on and off as long as ur lowbeams are on. If you keep the switch on "auto" or "fully on", the buzzing noise continues. However, if you turn the light switch completely off, the buzzing noise will go away. I have an appointment with bmw on monday morning. Will see what they say. I think it might have something to do with the radio or headlights. Faulty wires maybe...dunno?

I will try this, but reason I ruled out anything electrical is because when I rev, the noise is dependent on rpms.. ( at 1K rpm the noise disappears)

[RequestTheOverhead]

Hmm.... that's weird. It could be some electrical interference from a poorly shielded wire, or a high current wire, that closes to your front-center speaker wires. That's the only thing can think of that would cause the sound to start when the headlights are switched on or the revs are increased.

[cn555ic]

It is the electrical fan from the ecu box. That has been discusssed many times.

[str8flush]

Originally Posted by 1LUMI

I will try this, but reason I ruled out anything electrical is because when I rev, the noise is dependent on rpms.. ( at 1K rpm the noise disappears)

This because the noise from your engine is louder than the noise that is coming from the radio/centre console. Since 335s have low end torque, even at 1000rpm, the noise from the engine will be louder than the weird noise from the centre/radio console hence you think it's gone when it's actually still there. When you don't throttle, and your car is just cruising, the noise will appear again. Or when you are at a light, you'll hear it as well.

[Bagelfast]

Originally Posted by RequestTheOverhead

Hmm.... that's weird. It could be some electrical interference from a poorly shielded wire, or a high current wire, that closes to your front-center speaker wires. That's the only thing can think of that would cause the sound to start when the headlights are switched on or the revs are increased.

Tried with headlights on, off, every position, doesn't change or add to the noise.

Originally Posted by cn555ic

It is the electrical fan from the ecu box. That has been discusssed many times.

Would this fan be rev dependent? the sound comes and goes, and is only at idle.. And in N, I rev it and the noise goes along with the revs.

Originally Posted by petr_rsti

This because the noise from your engine is louder than the noise that is coming from the radio/centre console. Since 335s have low end torque, even at 1000rpm, the noise from the engine will be louder than the weird noise from the centre/radio console hence you think it's gone when it's actually still there. When you don't throttle, and your car is just cruising, the noise will appear again. Or when you are at a light, you'll hear it as well.

It happens at idle only, or below 1000 rpm.. Never during cruising..

I put the car in N, at idle it does it, and when I rev slightly it does it. I 100% can hear for sure it goes away when I pass 1K rpm..

I tried, AC on, off, raido on off, cd out, headlights on off, every position.. Nothing effects the sound.

Only when I rev lightly, the sound goes along with the revs.
And the sound comes and goes. when it wants. So im guessing something engine wise.

[cn555ic]

Originally Posted by 1LUMI

Tried with headlights on, off, every position, doesn't change or add to the noise.



Would this fan be rev dependent? the sound comes and goes, and is only at idle.. And in N, I rev it and the noise goes along with the revs.



It happens at idle only, or below 1000 rpm.. Never during cruising..

I put the car in N, at idle it does it, and when I rev slightly it does it. I 100% can hear for sure it goes away when I pass 1K rpm..



I tried, AC on, off, raido on off, cd out, headlights on off, every position.. Nothing effects the sound.

Only when I rev lightly, the sound goes along with the revs.
And the sound comes and goes. when it wants. So im guessing something engine wise.

Yes as you rev it the electric fan on mine seems to speed up and decrease as you are idling.

[AddictedToBavarian]

You are not alone my friend.

[Trojan4evr]

Totally Normal. I'e noticed it to. It's worse in N55.

[STooK]

Mine started happening as the weather started to get colder here. Usually in the morning, it appears at 1700-1900rpm and it's like a loud buzzing somewhere behind the center console. Not sure if it's the same noise everyone's talking about, but it's getting pretty annoying.

[Dark_Knight_335]

Originally Posted by Trojan4evr

Totally Normal. I'e noticed it to. It's worse in N55.

Damn right it is....

[str8flush]

I went to bmw dealer and they replaced the radio for me, but the faint buzzing noise behind the centre console is still there. I guess it's not the radio after all. I went back again and they re-checked the radio unit to see if any pins were loose and none were. The shop foreman said he heard it on the other 335s too and said it's no big deal. Btw the buzzing noise is still there. So it's normal?

[Wingman335]

Honestly, I thought it was only me who had this whine! I'm glad to see that I'm not the only one whose N55 experiences this.

I was thinking of taking it to the dealer but now it seems that its considered a "normal operation"

[str8flush]

Originally Posted by Wingman335

Honestly, I thought it was only me who had this whine! I'm glad to see that I'm not the only one whose N55 experiences this.

I was thinking of taking it to the dealer but now it seems that its considered a "normal operation"

There are couple 323s, 328s on our lot. I sat inside and they have no buzzing noise. That's why it's getting on my nerves -_-