[imyb]

Hello everyone,

I am hoping someone maybe able to shed some light on a noise which can be heard from my car whilst it is in motion.

Since September my car has been making a weird noise, below are the conditions I have identified:
1) inconsistent, some days there is a noise other days there isn't
2) if there is a noise, it is always during the first drive of the day
3) once the noise has come and gone even if it still for the same journey or subsequent journeys for same day, the noise will not return
4) when I open the window the noise is louder (as you will notice in recording)
5) the noise only appears when the car is in motion, never when it is stationary
6) noise happens on straights and bends
7) noise happens at low speeds and high speeds including the motorway, I have tested to 70MPH and if it is in the mood to make a noise it will do even at that speed

I am not sure if anyone has ever experienced anything similar but any insight will be useful.

I have linked a copy of the audio only from a drive I did two days ago.
The recording is cropped, for the first 3 minutes and 30 seconds there was no noise so I took that out, throughout this journey the noise comes and goes, it gets louder as I open window.
Once I reach my destination after this first drive of day, I go to several other destinations (same day) and there is no noise on those journeys.

Any insight is appreciated.

https://drive.google.com/file/d/1BB8...?usp=drive_web

Thank you

[mgmavant]

Interesting- have you tried to open the sunroof when the noise is there to see if it changes? Does the frequency or level change with a change in speed?

[emmix007]

have you checked AC fan blower?

[imyb]

Originally Posted by mgmavant

Interesting- have you tried to open the sunroof when the noise is there to see if it changes? Does the frequency or level change with a change in speed?

I haven't tried the sunroof, will try to see if that makes any changes.
The noise seems to come from under the car but I guess one never knows.

I think with acceleration the noise does change but I've not managed to get a recording of it doing so.

[imyb]

Originally Posted by emmix007

have you checked AC fan blower?

I haven't, can you tell me where I would need to check for this?

[emmix007]

Originally Posted by imyb

I haven't, can you tell me where I would need to check for this?

When the noise starts, turn off the Climate Control and check for the noise

[Marty in NY]

Originally Posted by imyb

Hello everyone, I am hoping someone maybe able to shed some light on a noise which can be heard from my car whilst it is in motion.

Thank you

FYI, you might want to remove your IP address from your location in the sidebar and add in your real location.

I listened to your audio clip, can you explain which noise I should be concentrating on? What does it sound like to you because I heard several noises?

[ef11]

I think he's referring to the low droning screeching sound...but yes, please provide what it sounds like to you because otherwise we don't know what to listen for.

Sounds almost like some motor is struggling...not sure.

Primary weird noise in my M50i is a slight whistling noise around 45-55 mph, and again at ~70. Commute to work is at 50 so was not too fun.

BMW had the car for about a week and replaced driver windshield trim, to no avail. Then they taped various parts of the front driver side and identified it to be coming from the mirror covers, so replaced that.

I still heard it to some degree, so purchased the black M mirror covers (off amazon for like $80), swapped them out, and it has helped but I still hear it from time to time.

[imyb]

Thanks for all replies and suggestions, I tried them all to no avail, the sunroof and ventilation made no difference.

It sounds to me like someone is blowing through a folded sheet of paper (something we used to do as kids).

I haven't been able to nail down what it is, BMW cannot figure it out unless I authorize an unlimited amount of diagnostics time with no guarantee of cause being identified. They thought it was an exhaust leak but after inspection tell me there is no leak and I would have to replace it at my own cost with no guarantee noise will be fixed.

The major issue, is the fact the noise is intermittent, if the noise does appear, once it has finished normally within first 10mins of the first drive of the day, it will not make the noise again for the whole day, regardless of how much I drive, which leads me to believe it must be something to do with a warmup process of the car, maybe, something that opens to let in air or a pump to circulate something on first warmup, I cannot figure it out.

I don't think it is an external part like side mirror or rubber around a windshield as the noise goes away and stays away after a 10 minute drive and the sounds seems to be coming from under vehicle.

Originally Posted by ef11

I think he's referring to the low droning screeching sound...but yes, please provide what it sounds like to you because otherwise we don't know what to listen for.

Sounds almost like some motor is struggling...not sure.

Primary weird noise in my M50i is a slight whistling noise around 45-55 mph, and again at ~70. Commute to work is at 50 so was not too fun.

BMW had the car for about a week and replaced driver windshield trim, to no avail. Then they taped various parts of the front driver side and identified it to be coming from the mirror covers, so replaced that.

I still heard it to some degree, so purchased the black M mirror covers (off amazon for like $80), swapped them out, and it has helped but I still hear it from time to time.

[Marty in NY]

Originally Posted by imyb

Thanks for all replies and suggestions, I tried them all to no avail, the sunroof and ventilation made no difference.

It sounds to me like someone is blowing through a folded sheet of paper (something we used to do as kids).

Ok, now that you have explained the noise a bit I was able to pick it out from the ambient. While I don't have an answer for you, I was reading back through your comments looking for hints and a pattern. Mostly you said it happens when cold and once warmed up its gone and stays gone the rest of the day, however, you also said .." inconsistent, some days there is a noise other days there isn't". So even when the car is cold, it doesn't make the noise on some days?? What state are you in?

I've summarized your observations as follows:
- if there is a noise, it is always during the first drive of the day
- when I open the window the noise is louder
- the noise only appears when the car is in motion
- the sunroof and ventilation made no difference

[krypttic]

Can you tell if the noise is under the hood? If so, can you loosen the oil cap momentarily to see if it goes away? If so, it’s the breather box.

[Marty in NY]

Originally Posted by krypttic

Can you tell if the noise is under the hood? If so, can you loosen the oil cap momentarily to see if it goes away? If so, it’s the breather box.

He said it only appears when the car is in motion. I was trying to draw a pattern but so far am coming up empty. I wonder if he was standing still and rev'd the engine to match the rpm's it sees when he's driving if he would hear the noise. To your point it does sorta sound like air intake but I ruled that out after summarizing his observations. Could there be something amuck with his engine air filter? But then why would it go away once warmed up? Let's see how he answers your question.

[COKen]

You could use something like the link below to locate the source of the sound. This one is a bit expensive, but much, much less than the dealer would charge you. You may also be able to find one that is less costly.

https://www.amazon.com/STEELMAN-0660...000IHIAES?th=1

[imyb]

Thank you for response and you are correct, even if it is a cold day (like it was today) the car did not make the noise all day. I am in London and not the US.

BMW has had my car in twice for this noise, total of 4 days and they were only able to hear the noise on one of the days (as they claim) but unfortunately they didn't record it.
They originally thought it was an exhaust leak from a seal (had exhaust replaced under warranty year before) and said they had applied some more sealant and to see if this would fix noise, it didn't so I took it back in.
The second time car went in they were unable to reproduce noise and said they checked for an exhaust leak and there is no leak, although even before I got out of BMW car park (on way home after picking up car) the car was making the same noises which BMW didn't hear

Originally Posted by Marty in NY

So even when the car is cold, it doesn't make the noise on some days?? What state are you in?

I've summarized your observations as follows:
- if there is a noise, it is always during the first drive of the day
- when I open the window the noise is louder
- the noise only appears when the car is in motion
- the sunroof and ventilation made no difference

[imyb]

Originally Posted by krypttic

Can you tell if the noise is under the hood? If so, can you loosen the oil cap momentarily to see if it goes away? If so, it’s the breather box.

I don't think it's from under the hood, I think it comes from under the front passenger side area and I seem to notice, when I speed up whilst it is making the noise the noise seems to also whine faster.
I'll try and get a recording of this.

[imyb]

Originally Posted by Marty in NY

He said it only appears when the car is in motion. I was trying to draw a pattern but so far am coming up empty. I wonder if he was standing still and rev'd the engine to match the rpm's it sees when he's driving if he would hear the noise. To your point it does sorta sound like air intake but I ruled that out after summarizing his observations. Could there be something amuck with his engine air filter? But then why would it go away once warmed up? Let's see how he answers your question.

I can try revving the engine whilst stationary to see if it will make the noise, will try that tomorrow.
Someone asked me at what speeds and how soon, sometimes it is within 10-20 seconds of journey starting and other times it can take 3-4 minutes before noise begins.
I don't think I have noticed the noise below speeds of 20 MPH.

[chrisado]

That sounds like a piece of moulding or rubber catching the wind. Look carefully at the winshield trim for a piece of rubber or the trim itself not lying flush. I heard this before on hondas when I was a tech years ago. It can be a mirror, side window trim, hood seal, etc but usually the windshield.