Weird noise emitted from my 750i when getting off the throttle.

[quackman]

Annoying problem I've noticed ever since I got my car about a month ago... there is a decently audible noise I hear when i let off the gas that gos for about 5-8 seconds. It happens pretty regularly and according to at least one other source it's not just a problem with my car:
From the Motor Trend article discussed in this thread http://www.7post.com/forums/showthread.php?t=268437 :
"Our test car even emitted an annoying background fan or gear whine that seemed to follow throttle movements."


After hearing it so many times, it sounds like it's coming from somewhere underneath the car, under the driver front seat area. But it doesn't seem like it's something inside the car. There appears to be nothing under the seat that would make that noise, especially the regularly specific times that it happens.

Does this happen to anyone else? I'm definitely going to mention it the next time I bring my car in to the dealer.

[xDrive50i]

Originally Posted by quackman

Annoying problem I've noticed ever since I got my car about a month ago... there is a decently audible noise I hear when i let off the gas that gos for about 5-8 seconds. It happens pretty regularly and according to at least one other source it's not just a problem with my car:
From the Motor Trend article discussed in this thread http://www.7post.com/forums/showthread.php?t=268437 :
"Our test car even emitted an annoying background fan or gear whine that seemed to follow throttle movements."


After hearing it so many times, it sounds like it's coming from somewhere underneath the car, under the driver front seat area. But it doesn't seem like it's something inside the car. There appears to be nothing under the seat that would make that noise, especially the regularly specific times that it happens.

Does this happen to anyone else? I'm definitely going to mention it the next time I bring my car in to the dealer.

Tranny noise maybe???

[SpotM5]

Originally Posted by xDrive50i

Tranny noise maybe???

Great news XDrive!!!!!!!!!!!!!!!!! you better go down their early to check it out

re the noise - ive posted on this before - it is just the powertrain. it doesn't seem to affect anything - but if you find something out from the dealer please let us know

[spidey 7]

I've had my 750i for two months and it is my only complaint. The noise is a spooling sound, the pitch increases as the rpms increase. I'm sure it's nothing and the car is no less fantastic to drive, but expectations are so high that any small glitch is magnified. I don't usually notice too often and never on the highway.
Still the best car I've ever driven or owned.

[xDrive50i]

Originally Posted by spidey 7

I've had my 750i for two months and it is my only complaint. The noise is a spooling sound, the pitch increases as the rpms increase. I'm sure it's nothing and the car is no less fantastic to drive, but expectations are so high that any small glitch is magnified. I don't usually notice too often and never on the highway.
Still the best car I've ever driven or owned.

I picked up my 750i individual today and drove it (by my lonesome) for quite some time and listened for any abnormal noises. I can happily report that the car has none

[SpotM5]

Originally Posted by xDrive50i

I picked up my 750i individual today and drove it (by my lonesome) for quite some time and listened for any abnormal noises. I can happily report that the car has none

It may take a while to hear it- give it some time...

[spidey 7]

Don't let all of this discussion distract you from enjoying your new car. You may not really notice the sound at all. I don't hear it until the engine has warmed up, usually after freeway driving.

[xDrive50i]

Originally Posted by SpotM5

It may take a while to hear it- give it some time...

I think I know what sound you are referring to. I hear it all the time on my wife's xDrive car and it is definitely the transmission. It sounds like a whiny kind of noise fairly subdued but still noticeable when you drive with the windows closed and no music or other source that is louder than this noise. In other words all you hear is the engine and of course the noise we are talking about here. This noise is usually only noticeable when you let the engine free run or use engine braking, e.g. approaching an intersection by letting the car roll to it with the foot off the accelerator. I don't really hear it while accelerating as the engine sound usually overpowers the transmission noise, however it is quite noticeable when you decelerate by using the engine rather than the brakes. I hope I explained it accurately enough to make sense to others

[xDrive50i]

Originally Posted by spidey 7

Don't let all of this discussion distract you from enjoying your new car. You may not really notice the sound at all. I don't hear it until the engine has warmed up, usually after freeway driving.

Oh I wouldn't! And believe me, even if it did have some transmission noise, I would still drive this car

[SpotM5]

Originally Posted by xDrive50i

Oh I wouldn't! And believe me, even if it did have some transmission noise, I would still drive this car

my feeling is that there is no impact on the car - just a powertrain noise! enjoy and more pics please!

[quackman]

Noise fixed!
I brought it to the dealer to complain and first they removed the seat to see if the noise was from something inside the car. It was not.
Repair order stated:
"Trace noise comic from the plactic fuel line pressure buildup when gas pedal is released... Remove Fuel line from right side fuel pump and install foam insulation around the fuel line... Reinstall line and recheck Noise is gone"
So the noise was coming from underneath the car. And now it's gone.

[spidey 7]

I wonder if the sound you were hearing was different than those reported elsewhere. The whining sound I hear is coming from the engine compartment for sure and is clearly related to the rpms. I would like to correct the sound if at all possible.

[xDrive50i]

Well, I had the car for a month (actually tomorrow will be the 1st month anniversary) and I'm just shy of 750 miles. As you can tell, I don't drive the car that much, although I wish I could and I do any chance I get.

I'm happy to report that the car is as silent as the day I picked it up. No abnormal noises of any kind!