Buzzing noise in cabin

I need help identifying what this buzzing noise is inside the cabin. I hear it on the Left side of the car. It usually happens a minute after I start the car up after unfolding the mirrors.


(Might have to turn up the volume to hear the electronic buzzing noise)

Check out this thread here.

heyitsrev wrote

I need help identifying what this buzzing noise is inside the cabin. I hear it on the right side of the car. It usually happens a minute after I start the car up after unfolding the mirrors.

(Might have to turn up the volume to hear the electronic buzzing noise)

You mean the *LEFT side of the car.

I think that could very well be the vacuum pump as well. It is located in the LEFT front fender area.

During your video, I don't imagine you were pressing the brake pedal on and off, right? You could very well have a vacuum leak causing the vacuum pump to cycle constantly. Or it could also be an issue with the vacuum pressure sensor. I'm curious if there is a panel in INPA or ISTA to observe this very thing that could possibly help you diagnose properly...hmm.

heyitsrev wrote

I need help identifying what this buzzing noise is inside the cabin. I hear it on the Left side of the car. It usually happens a minute after I start the car up after unfolding the mirrors.

(Might have to turn up the volume to hear the electronic buzzing noise)

Brake vacuum pump. If you're hearing it consistently every time you start the car, your brake vacuum sensor is on its way out. You will be getting limp mode soon. Did you recently change your brake fluid? The sensor is easy to damage from fluid leaking onto it if the mech is not careful during brake fluid change. Good thing is that it's a cheap fix cos now you can buy just the sensor instead of the entire hose + sensor.

Redd wrote

Brake vacuum pump. If you're hearing it consistently every time you start the car, your brake vacuum sensor is on its way out. You will be getting limp mode soon. Did you recently change your brake fluid? The sensor is easy to damage from fluid leaking onto it if the mech is not careful during brake fluid change. Good thing is that it's a cheap fix cos now you can buy just the sensor instead of the entire hose + sensor.

Is this the cheapest sensor I can get?
https://www.fcpeuro.com/products/bmw-manifold-differential-pressure-sensor-13628617097

Is the sensor itself replaceable? I see it only available as an assembly.

$223
Here:
https://www.fcpeuro.com/products/bmw-vacuum-line-with-pressure-sensor-34302283605

RocketyMan wrote

Is the sensor itself replaceable? I see it only available as an assembly.

$223
Here:
https://www.fcpeuro.com/products/bmw-vacuum-line-with-pressure-sensor-34302283605

From this Thread, people seem to buy just the diff sensor since it has the same part number.

https://www.m3post.com/forums/showthread.php?t=1338052&page=3

heyitsrev wrote

From this Thread, people seem to buy just the diff sensor since it has the same part number.

https://www.m3post.com/forums/showthread.php?t=1338052&page=3

Oh sweet!! Try it out!

BTW, I tried looking in ISTA and INPA for a panel to run the vacuum pump. I cannot find ANYTHING to try and test the pump.

Whenever I try to do a search, "FUEL" pump comes up...even when I explicitly searched for "vacuum." -_-