whistling/howling noise from back of car. fuel pump?

[kloftus1044]

About a month ago my 2010 135i started making a sort of howling noise that seems to emanate from the back of the car. The noise sounds a bit like the sound you get when you blow into a 2 liter bottle.

Some observations about the noise:

• I don't notice the sound if the car is cold
• it becomes noticeable at around 50-55mph
• it does not change frequency regardless of speed
• it seems to go away when throttle is applied and re-appear when lifting off
• first noticed it after a very spirited drive thru the canyons one night

About the car:
currently has RFTs
has 20000 miles
automatic with steering wheel shifters
doesn't seem to have any fuel delivery issues.

Its not much to go on, but could the problem be fuel pump related? Maybe something else? Any input is welcome.

Kevin

[vertebra]

I had a rear differential replaced that was more like a whistle or whine. Check out this thread and listen to the sound file to see if it is the same noise. http://www.e90post.com/forums/showthread.php?t=471838


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[Mr. Toad]

I posted this shortly after acquiring my car:

http://www.1addicts.com/forums/showthread.php?t=779425

If my description of the noise sounds similar to what you're experiencing, mine was diagnosed and (temporarily) eliminated by dealer replacement of the differential. I say "temporarily" because the fix doesn't last but about a month or so. Mine was replaced this past February, and while it's not currently as prominent as it originally was, the sound has started to come back.

[kloftus1044]

[quote=vertebra;14313254]I had a rear differential replaced that was more like a whistle or whine. Check out this thread and listen to the sound file to see if it is the same noise. http://www.e90post.com/forums/showthread.php?t=471838

That's the sound all right: rear differential. How very disappointing. I don't know how to proceed. The comments on that thread don't paint a very rosy picture.

[kloftus1044]

Originally Posted by rjg

I posted this shortly after acquiring my car:

http://www.1addicts.com/forums/showthread.php?t=779425

If my description of the noise sounds similar to what you're experiencing, mine was diagnosed and (temporarily) eliminated by dealer replacement of the differential. I say "temporarily" because the fix doesn't last but about a month or so. Mine was replaced this past February, and while it's not currently as prominent as it originally was, the sound has started to come back.

Yep, that's the problem. How many miles on the new differential before the sound started to come back?

[doublevanosrc]

Dead hooker??

[gregthegr8]

Originally Posted by doublevanosrc

Dead hooker??

Dead hookers don't make noises, at least in my experience...unless you go over some speed bumps or hit a pothole. But then it's more of a thumping noise, not a whistle or whine.

[Mr. Toad]

Originally Posted by kloftus1044

Yep, that's the problem. How many miles on the new differential before the sound started to come back?

I've now put about 5,000 miles on my car since the differential was replaced. I'd say the noise reappeared at around 1,000 miles, but it was relatively unobtrusive compared to what it had been and it continues to be so to this day (i.e., it's still not noisy enough to make me bring it back in).

I read a bit of the other thread posted here and noticed that several people mentioned their dealership refusing to perform replacements for this issue; that was not my experience. My car is a CPO, and the dealership from which I bought it diagnosed the problem, ordered the differential from Germany, and then gave me a loaner. I didn't get my car back for almost two weeks, but I had a 2012 model to drive the whole time so I had no complaints.

[nnguyen04]

Originally Posted by gregthegr8

Dead hookers don't make noises, at least in my experience...unless you go over some speed bumps or hit a pothole. But then it's more of a thumping noise, not a whistle or whine.

^ lollol

[vertebra]

Originally Posted by rjg

I've now put about 5,000 miles on my car since the differential was replaced. I'd say the noise reappeared at around 1,000 miles, but it was relatively unobtrusive compared to what it had been and it continues to be so to this day (i.e., it's still not noisy enough to make me bring it back in).

I read a bit of the other thread posted here and noticed that several people mentioned their dealership refusing to perform replacements for this issue; that was not my experience. My car is a CPO, and the dealership from which I bought it diagnosed the problem, ordered the differential from Germany, and then gave me a loaner. I didn't get my car back for almost two weeks, but I had a 2012 model to drive the whole time so I had no complaints.

This is my experience getting the diff replaced on my 2010 CPO. Brought car in drove around with several SA's and mechanics. Left the car there for a a few days received a call that it was the brakes and that it is fixed. Upon pick up the noise was still there. Left the car, 4 days later I was told they had to adjust the emergency brake cable. Upon pick up the noise was still there. I was livid the dealer was ready to get me another car but there was nothing on the lot comparable. Confidentially speaking an employee told me that they know what the problem is right away but BMW NA does not like to replace the diff so they make the mechanics try the other BS first. I don't know if that is true but they did replace the Diff and the noise is gone... so far.