[XxThe_RemedyXx]

Just started experiencing this sound in my 335. Haven't been able to track it down and there isn't too much information on it. I was wondering if anyone experienced this?

[Newman1]

Coincidentally, my car is at the dealership getting inspected for the same sound, which it's been doing for about six months now. You can make it go away by simply turning on your climate control (a/c) and it stops immediately. But I also took a video of it, showed it to my dealership, and they said they can't do anything unless they hear it in person. Unfortunately it decided not to replicate itself when I took a tech for a spin, so I'm expecting a call back saying "could not duplicate, nothing to repair."

If you or anyone here knows what this could be from, and the solution, other than turning on and off the a/c, I'd be happy to know.

[twonb1]

Well my car is starting week 3 at the dealership with no luck fixing the sound just yet. Keep me updated if your figures it out

[Sarastro]

I've got this as well. It seems to be linked to the aircon fan, if I turn the fan off it goes away. However - oddly - it goes away under acceleration, and comes back when I'm decelerating or coasting. Local dealer at a loss, but wants to take the entire dash apart to investigate. It doesn't bug me that much!

[Zap]

Checking in here, our car ('14 335i) has the same problem. Troubleshooting has revealed that letting off the gas intensifies the sound. The dealership found an A/C related SIB that added a solenoid in-line, but that was performed on the car and the problem still persists.

I've seen two other threads, one references the expansion valve as a problem and another says that a rear diff replacement remedied the issue. Not sure if they are all the same noise, but since we're at a loss here if anyone else can weigh in it would be appreciated. Have another service appointment coming up to attempt to further troubleshoot.

[Kailec]

I had this issue today too. Only just started, not sure if it's related to cold weather or what...

[Sarastro]

I live in Cyprus, today was yet another day north of 20C, and it whistles here - so probably not the cold

[XxThe_RemedyXx]

Have my car in for this today, SA thinks it's the differential

[Buse]

I have the issue as well, but have not attempted to trouble shoot or take it in to the shop.

For the people that are saying differential, what part of a differential would cause this?

[Zap]

Originally Posted by Buse

I have the issue as well, but have not attempted to trouble shoot or take it in to the shop.

For the people that are saying differential, what part of a differential would cause this?

Between the fairly consistent pitched tone, intermittent noise, etc I am at a loss as well.

Someone else has suggested the cause could be the EfficientDynamics system (regenerative braking). I'll have to pay attention to this the next time I hear it.

Regarding temperature, it seems to happen between 30-50 degrees F for our car. It was fairly nonexistent during the summer, and I fear that it may disappear before our appointment as the cold has set in.

[Capt Awesome]

2011 E90 Sedan here... oddly enough I've had this sound for a couple weeks and I just came back from the garage after fixing it. For me it was the cabin blower motor. I removed it (5 mins), lubed all the bearings with WD40, and put it back in. Took it for a test drive and the sound is gone.
Follow this tutorial to remove your blower:

I had that whistling sound when coming to a stop. It mostly went away when I accelerated and went away completely when the climate control was turned off.

Hope that helps.

[XxThe_RemedyXx]

Originally Posted by Capt Awesome

2011 E90 Sedan here... oddly enough I've had this sound for a couple weeks and I just came back from the garage after fixing it. For me it was the cabin blower motor. I removed it (5 mins), lubed all the bearings with WD40, and put it back in. Took it for a test drive and the sound is gone.
Follow this tutorial to remove your blower:

I had that whistling sound when coming to a stop. It mostly went away when I accelerated and went away completely when the climate control was turned off.

Hope that helps.

This is great but unfortunately this cant be the case for mine. I recently had my blower motor replaced by BMW due to failure.

[sspade]

Does that Youtube video work for an F30 as well?

[twonb1]

So remedy i got my car back from the dealer and the first noise that I had was solved by replacing the rear diff. Now my car is my the exact same noise in your video. I will try to upload a video for comparison.

[XxThe_RemedyXx]

Originally Posted by twonb1

So remedy i got my car back from the dealer and the first noise that I had was solved by replacing the rear diff. Now my car is my the exact same noise in your video. I will try to upload a video for comparison.

Damn I'm sorry to hear that. I honestly have no clue what this damn noise can be. My car is at BMW as well and they're trying to figure it out.

[twonb1]

Here's what mines sounds like

[drewkelly]

Originally Posted by XxThe_RemedyXx

Just started experiencing this sound in my 335. Haven't been able to track it down and there isn't too much information on it. I was wondering if anyone experienced this?

Friend of mine had a 2013 328i xDrive and the day he drove it home from the dealer heard a "tea kettle" going off in the roof. After multiple trips back to the dealer, they FINALLY found that it was a gasket in the sunroof and replaced it. That fixed him up...

[XxThe_RemedyXx]

Originally Posted by twonb1

Here's what mines sounds like

EXACTLY what mine sounds like. It drives me mad!

[Zap]

The video posted is exactly the same as the sound our '14 makes.

However, the plot thickens - I experienced this sound in a different way for the first time this week. I got into the car after unlocking with Comfort Access. The BMW logo was showing in the center of the cluster, but I had not pushed the start stop, and no accessories were on.

I had to respond to a few messages on my phone, so I did this and during that time, even though I hadn't started the accessories on the vehicle, the noise occurred!

I was floored, as prior to this it had only happened when driving and when the engine was running. My suspicion was always on some type of electronic malfunction inside the cabin, but this seems to be proof of it.

We've had a head unit replacement in the past due to an unrelated issue. We're going to be replacing another cabin component next week, so I'll have an update as to whether that makes any difference.

[Sarastro]

I'm starting to suspect Zap is correct - I'm not sure this is the fan motor.

E93, 2010 here. EXACTLY the same noise as the videos.

With the fan on, I get the noise. But oddly, I get the EXACTLY the same noise irrespective of fan speed. I would have thought that the noise would change at different fan levels?

The noise goes away under acceleration, and comes back when I'm decelerating or coasting.

It's nice and warm where I live so we can discount a temperature related issue I suspect.

Wonder if there is a capacitor that is supposed to suppress something that is giving up the ghost?

[Zap]

Originally Posted by Sarastro

I'm starting to suspect Zap is correct - I'm not sure this is the fan motor.

With the fan on, I get the noise. But oddly, I get the EXACTLY the same noise irrespective of fan speed. I would have thought that the noise would change at different fan levels?

The noise goes away under acceleration, and comes back when I'm decelerating or coasting.

It's nice and warm where I live so we can discount a temperature related issue I suspect.

Wonder if there is a capacitor that is supposed to suppress something that is giving up the ghost?

This is interesting, as we've owned 4 BMWs (2 e92 335i N54, 1 e93 M3, 1 F30 335i xDrive) and only the F30 has had this problem.

We get the noise with the fan off, and the pitch is always the same. It does seem to consistently go away or get more faint with acceleration.

If you're in a fairly consistent temperature range, I'd suspect it will happen more frequently. It seems like when it is very cold here the problem goes away.

I'm starting to wonder if there is a power supply issue, or maybe a singing inductor coil in something electronic. I've seen inductors resonate in various devices in the past, and they make a high pitched sound.

[uclanakf30]

Anyone have luck in finding out what causes this whistling sound?

Originally Posted by XxThe_RemedyXx

Just started experiencing this sound in my 335. Haven't been able to track it down and there isn't too much information on it. I was wondering if anyone experienced this?