2011 e71 X6 screaming noise

[andym3]

My car occasionally makes a screaming noise. It sounds like it is from the bottom of the car. I opened the hood, the noise is not as loud. But underneath is loud. It doesn't happen all the time. May be twice a month? It only happens when starting the car. If I press the gas pedal, the sounds goes away. When I release gas pedal, sound sometimes comes back. There is no engine light or any kind of warning message. I do oil change regularly. What could it be? Any help would be appreciated.

Link is a video of the noise:

[gitee]

Originally Posted by andym3

My car occasionally makes a screaming noise. It sounds like it is from the bottom of the car. I opened the hood, the noise is not as loud. But underneath is loud. It doesn't happen all the time. May be twice a month? It only happens when starting the car. If I press the gas pedal, the sounds goes away. When I release gas pedal, sound sometimes comes back. There is no engine light or any kind of warning message. I do oil change regularly. What could it be? Any help would be appreciated.

Link is a video of the noise:

DIY: Understanding the N55 PCV Valve of Doom https://www.e90post.com/forums/showthread.php?t=1197666

[mitch808]

I have something VERY similar, and my dealer can't reproduce it.

On deceleration, or in mild traffic say up to 20MPH, while coasting; it''ll squeal. Like a belt squeal. But it's not constant.

Lightly accelerate, and it goes away. At speed, I don't think it ever happens. Only while under 30MPH or so, usually coasting or idle. I thought on hotter days it was more reproducible, but on cold days it happens too.

While getting other servicing done, the dealer couldn't reproduce it.

It's been going on for 20k miles and more than a year now.

[racermp]

Probably the boost pressure converter / boost solenoid. Small plastic thing. Diaphram breaks inside due to age. Creates this whistle sound. It's on the passenger side above the turbo is you have a N55. Mounted on head right below valve cover.

Google it

Easy to change, 10 mm nuts , 2 vacuum tubes, one wire connecter. Google it. Get from fcp make sure ur manifold is cold or forever feel the burnnnn.

[cbakking]

I believe this is what's happening to my X5M as well, only on a hot day when car has been sitting on the sun or on a warm start (car has been parked only for an hour or so then restarted), high pitch belt squeal like noise comes on for ~30 sec then gone, took it to dealer (when it was still on warranty) many times, they were never able to reproduce the noise.
Is the fix simple on X5M as well?

[pearlpower]

Originally Posted by cbakking

I believe this is what's happening to my X5M as well, only on a hot day when car has been sitting on the sun or on a warm start (car has been parked only for an hour or so then restarted), high pitch belt squeal like noise comes on for ~30 sec then gone, took it to dealer (when it was still on warranty) many times, they were never able to reproduce the noise.
Is the fix simple on X5M as well?

Any remedy on this? Mine is similar, only at idle, and only once warm.

[9vapors]

Originally Posted by pearlpower

Any remedy on this? Mine is similar, only at idle, and only once warm.

vacuum leak that's either sealing up when it's warm or you just can't hear it after cold start.

[pearlpower]

Originally Posted by 9vapors

vacuum leak that's either sealing up when it's warm or you just can't hear it after cold start.

Only when vehicle has been driven and nice and warm. Cold, no noise, even after 10 minutes or so. Drive it for 20 minutes......noise, again only at idle. Not steering dependent, new belts, new tensioner. AC on/off makes no difference.

[9vapors]

Originally Posted by pearlpower

Only when vehicle has been driven and nice and warm. Cold, no noise, even after 10 minutes or so. Drive it for 20 minutes......noise, again only at idle. Not steering dependent, new belts, new tensioner. AC on/off makes no difference.

Would have it smoke tested or make one yourself to test. I would put $ on it being part of the CCV system has a crack... really common screaming sound you're referencing.

[Lviv777]

Had kinda of a similar problem, following thread hopefully a fix is found.

[pearlpower]

Originally Posted by 9vapors

Would have it smoke tested or make one yourself to test. I would put $ on it being part of the CCV system has a crack... really common screaming sound you're referencing.

No codes, pending or otherwise, it still pulls very strong. Idle is smooth as ever, no issues. Just the noise, not a whistle indicative of the one of the hoses going out-all 3 are new. Nowhere nearly as loud as the video above.

The harder I drive it, the louder the noise it seems. But will take a closer look one of these days. I drive it perhaps one day a week.

[pearlpower]

Link to a short video, you can hear the faint whine at low idle.

[yco]

assuming there is not problem with the shaft and diff cause then the problem wouldnt only be a noise.. i strongly believe it can be the fuel pump in the fuel tank.. this noise is typical with going bad to worse fuel pumps..

[9vapors]

Originally Posted by pearlpower

Link to a short video, you can hear the faint whine at low idle.

Sounds like you have a small dog stuck in there... seriously though, I still would just go through and pop off the engine cover, intake plastics and see if you can hear where it's coming from more.

[mirob]

I've had this issue for about 18 months now. Had a leaking vacuum pump, replaced it just before it got cold and it seemed like the noise went away with it. However, as soon as the warm weather returned, the noise returned.

This is my original thread below. I've dealt with a host of CCV leaks before and usually it's a whistling sound when a pipe cracks but I took it to an indy regardless and they did a smoke test and a compression test and everything checked out. Truck runs fine with no issues.

I was leaning towards pulleys/belts again but someone on here said they replaced theirs to no avail. Let's see if we can sort this out collectively...

https://www.xbimmers.com/forums/show....php?t=1467112

[pearlpower]

Originally Posted by mirob

I've had this issue for about 18 months now. Had a leaking vacuum pump, replaced it just before it got cold and it seemed like the noise went away with it. However, as soon as the warm weather returned, the noise returned.

This is my original thread below. I've dealt with a host of CCV leaks before and usually it's a whistling sound when a pipe cracks but I took it to an indy regardless and they did a smoke test and a compression test and everything checked out. Truck runs fine with no issues.

I was leaning towards pulleys/belts again but someone on here said they replaced theirs to no avail. Let's see if we can sort this out collectively...

https://www.xbimmers.com/forums/show....php?t=1467112

Sounds just like my noise, only at idle. It is a little louder with the AC off as the revs drop a bit. The higher the RPM the lower the sound. No noise above 900/1000 rpm. I might smoke test.

[lucaX6]

I have this issue happening now in my 2013 X6, its much louder then most of the video/audio clips in this post.
My mechanic has already indicated I need a valve cover replacement (already replaced in 2020) so I am annoyed and hesitant to do this repair right away.
What is any potential damage or long term damage to the engine if I leave it for a bit and continue driving?
Will post audio clip of engine squeeling, screaming soon.

*Update*
The valve cover diaphragm was ripped... in the shop now. $1,300 CAD

[mg3]

Sorry for the ignorance but can you provide more info on what part the Valve cover Diaphragm is ??

I had a noise like this and it was a loose intake boot (The part between the filter and turbo)