[warlockuy]

Buzzing behind the dashboard

Bmw e90 2005

Hello
This is something crazy
Summer is coming and I have only now used it almost to the maximum.
When the car goes 50 60 km/h
With the air conditioning with the AC off, and in the last two speeds blower.
A hum appears as if from the dashboard.
It sounds like a fan sound.
If the car is stopped it doesn't do it.
If the ac is on it doesn't do it.
If you accelerate in parking it doesn't do it.

If it is stopped, you turn the air to Maximum and you can't even hear it, the blower is silent.

I know it's hard to explain, but it seems like a fan or interference.

Which may be ?

If you want, I'll make a video to see if I can record it driving.

[Our03z4]

I would assume it's a vent flap not closing. Doubt it's vac assisted but if it is that would explain when you accelerate it goes away. Do your defrosters work right?

[warlockuy]

Originally Posted by Our03z4

I would assume it's a vent flap not closing. Doubt it's vac assisted but if it is that would explain when you accelerate it goes away. Do your defrosters work right?

Hello
sorry my english
It's when I accelerate after passing a certain speed or certain rpm, I'm not very sure.

But I clarify
It is with the AC off and only the blower on

If I am parked there is no strange noise

If I accelerate it appears but only in the last two speeds of the blower

The defrost works perfectly

If I turn on the AC this never happens.

The hatches close well when changing from one position to another.

It's like a noise behind the speedometer or so it seems.

algo loco jaja

[warlockuy]

New data

I did several tests, it is only felt when the middle button in the first image is activated
Little arrow on the right that blows air through the front of the dash.

If you select any other, arrow up, air comes out from above, or arrow down through the foot area, it does not.
Now more strangely, if you select the one that makes noise, arrow to the right, but you select recirculate the air, it doesn't.

If you select AC on it doesn't make noise.

So it is only when the first image is as is, I leave a video that the sound is heard.

image : https://drive.google.com/file/d/1A3s...ew?usp=sharing

Video 1 : https://drive.google.com/file/d/1jpJ...ew?usp=sharing

Video 2 https://drive.google.com/file/d/1w7h...ew?usp=sharing

[warlockuy]

Update
This sound only appears when the ambient temperature is more than 30 degrees.
That's why I only started listening to it now in the summer.
With 25 degrees it doesn't.
strange but well it's nothing serious

[carseatsm5]

Originally Posted by warlockuy

New data

I did several tests, it is only felt when the middle button in the first image is activated
Little arrow on the right that blows air through the front of the dash.

If you select any other, arrow up, air comes out from above, or arrow down through the foot area, it does not.
Now more strangely, if you select the one that makes noise, arrow to the right, but you select recirculate the air, it doesn't.

If you select AC on it doesn't make noise.

So it is only when the first image is as is, I leave a video that the sound is heard.

image : https://drive.google.com/file/d/1A3s...ew?usp=sharing

Video 1 : https://drive.google.com/file/d/1jpJ...ew?usp=sharing

Video 2 https://drive.google.com/file/d/1w7h...ew?usp=sharing

Look at all those beautiful knobs and buttons.

[Tejas1836]

Does it occur in both recirculate and fresh air modes?

[warlockuy]

Originally Posted by Tejas1836

Does it occur in both recirculate and fresh air modes?

hi

Happy New Year

Only with fresh air

It doesn't happen with recirculation.
And neither with the air conditioning.
But the strange thing is that fresh air, from above or through the feet, does not pass either.
It's only when it's pointing to the middle

[warlockuy]

Originally Posted by carseatsm5

Look at all those beautiful knobs and buttons.

ha ha ha
They are all the same.
For now they work fine.
I'm going to go check the air conditioning and see if it needs to be recharged, summer is coming in my country.
Happy New Year