[toksis]

Hello Guys, My E90 N46 engine has a strange sound. What could this oooh sound be? Thanks.

https://www.youtube.com/watch?v=zcAnALdOm5s

[nsjames]

does it change with RPM?

I had an oil filter cause a screeching noise on my n52.
and any sort of slight intake/pcv leak will cause noises like that.

you need to pnpoint where the noise comes from.

[toksis]

During high revs, the woooh sound also increase frequency pitch becomes high.

high rev


I also noticed when I start the car by pressing the start button without pressing the brake. I hear a high frequency sound and it will only stop after a loud plastic clang. I also recorded it here.

whistle sound

What could this sounds be?

[nsjames]

again, you need to pinpoint the component making the sound, or at least narrow it down to a general area in the engine bay using mechanics stethoscope or a screwdriver.

there are multiple possibilities.

[toksis]

I will check how to do that sthetoscope thingy. thanks

[toksis]

Hello, I bought a stethoscope and discovered where the sound is.

It is very high on the inlet manifold and not so high in the engine itself where the manifold is attached. I also put the stethoscope in the DISA valve or parts near it I can hear the high frequency sound.

I also attached some pictures for further clarification.





https://ibb.co/mCVJn0

https://ibb.co/dbSL0L