135i slight whooping sound

[roadcarver]

I have a 13 135i that I have had for a couple of month now and love it. However, over the last few weeks I have noticed a slight whooping sound which almost sounds like a little bird on occasion while driving it. It is very intermittent. I have a manual transmission and it seems to occur while cruising along between 2000 and 3000rpm with light throttle application but not always. I can not even hear it with the radio on. It does not do this at interstate constant speeds and seems to somewhat follow light throttle application. It sounds like a small amount of air possible going through a gate or hose. My wife has a 13 335i and it does not do this. The noise seems to occur most often going around slight curves with on and off light throttle. The dealer seems uncertain and I have not been able to replicate it yet for them upon visit. Any ideas from anyone what it could be and if it is normal? I initially thought it might be air moving through the wastegate or bov or maybe even a slight leak in a vacuum line. Thanks

[jester17]

If possible, have someone ride with you who can take a smart phone video; I've done this with a few issues, and the SA was grateful to have real-time evidence of what I was experiencing...

[Bama335]

mine does this at times as well - not always. It seems more obvious when you're in the passenger seat

I figured it was a BOV or something - none of the 4 other BMW turbos (2 x N54 and 2 x N55) I've had did this, but this is the first one with the PPK, I wondered if that was the reason

[roadcarver]

Originally Posted by Bama335

mine does this at times as well - not always. It seems more obvious when you're in the passenger seat

I figured it was a BOV or something - none of the 4 other BMW turbos (2 x N54 and 2 x N55) I've had did this, but this is the first one with the PPK, I wondered if that was the reason

Thanks BAMA, I cant believe I just typed that being a Vols fan, ha,ha. Mine only does it sometimes also. Is it just a faint noise in yours also? The best way I can describe it is as a very quite whoop,whoop that sounds like it would be produced by air. I was also thinking wastegate or BOV also. One SA told me it was normal in the 135i because it is set up differently than the 335i even though it is the same engine. Another one told me that the noise was probably not normal. I am leaning towards it being normal right now. I just don't want to waste time at the dealer anymore if it is normal. How are you enjoying your car? I might PPK in a couple of months, how is the throttle response with PPK? Thanks

[roadcarver]

Originally Posted by Bama335

mine does this at times as well - not always. It seems more obvious when you're in the passenger seat

I figured it was a BOV or something - none of the 4 other BMW turbos (2 x N54 and 2 x N55) I've had did this, but this is the first one with the PPK, I wondered if that was the reason

Oh yeah, I forgot to ask you if your previous n55's were in a 135i or some other model? Just curious to know if the first SA might have been right. Thanks for your responses

[roadcarver]

Originally Posted by jester17

If possible, have someone ride with you who can take a smart phone video; I've done this with a few issues, and the SA was grateful to have real-time evidence of what I was experiencing...

Good suggestion, however I am not sure if the smart phone would pick it up as it is such a low noise that I can barely hear it even with the radio off. Thank you

[Bama335]

Originally Posted by roadcarver

Thanks BAMA, I cant believe I just typed that being a Vols fan, ha,ha. Mine only does it sometimes also. Is it just a faint noise in yours also? The best way I can describe it is as a very quite whoop,whoop that sounds like it would be produced by air. I was also thinking wastegate or BOV also. One SA told me it was normal in the 135i because it is set up differently than the 335i even though it is the same engine. Another one told me that the noise was probably not normal. I am leaning towards it being normal right now. I just don't want to waste time at the dealer anymore if it is normal. How are you enjoying your car? I might PPK in a couple of months, how is the throttle response with PPK? Thanks

Mine resembles the whistle or bird you mentioned, very faint, and typically when i'm getting off the throttle after a spirited shift, etc.

The other two N55 I mentioned are the one in my current 2012 135iC DCT and a 2013 F30 MT6 that I no longer have.

I'm getting the oil changed Friday for 1,200 mi service at the local dealer, I will ask them their thoughts. The car is running great, so not thinking it's much of an issue at this point.

Throttle response in the "is" could be better, but the car is still learning my driving habits - the DCT vert response was lousy when new, but 2 yrs of thrashing it has it pretty good now. Is it as good as my buddy's E36 M3...um, no, but better than it was

[roadcarver]

Originally Posted by Bama335

Mine resembles the whistle or bird you mentioned, very faint, and typically when i'm getting off the throttle after a spirited shift, etc.

The other two N55 I mentioned are the one in my current 2012 135iC DCT and a 2013 F30 MT6 that I no longer have.

I'm getting the oil changed Friday for 1,200 mi service at the local dealer, I will ask them their thoughts. The car is running great, so not thinking it's much of an issue at this point.

Throttle response in the "is" could be better, but the car is still learning my driving habits - the DCT vert response was lousy when new, but 2 yrs of thrashing it has it pretty good now. Is it as good as my buddy's E36 M3...um, no, but better than it was

I would greatly appreciate it if you could share what they tell you Friday. My throttle response seems to be a little erratic. Sometimes it is very good and other times it is a little slow, very strange but still a very fun car. Thank you

[Andrewcoja]

Originally Posted by Bama335

Mine resembles the whistle or bird you mentioned, very faint, and typically when i'm getting off the throttle after a spirited shift, etc.

The other two N55 I mentioned are the one in my current 2012 135iC DCT and a 2013 F30 MT6 that I no longer have.

I'm getting the oil changed Friday for 1,200 mi service at the local dealer, I will ask them their thoughts. The car is running great, so not thinking it's much of an issue at this point.

Throttle response in the "is" could be better, but the car is still learning my driving habits - the DCT vert response was lousy when new, but 2 yrs of thrashing it has it pretty good now. Is it as good as my buddy's E36 M3...um, no, but better than it was

Is it long or quick. If you are letting off the throttle, sounds like it is the blow off valve.

[Bama335]

Originally Posted by Andrewcoja

Is it long or quick. If you are letting off the throttle, sounds like it is the blow off valve.

Relatively quick - maybe a second at most. I figured it was the BOV as well.

If I have the windows down or the stereo turned on, I usually don't hear it.

[titancrusher1]

Its the blow off valve. If you think it needs to be checked have the dealership look at it

[roadcarver]

It sounds like BAMA is having the exact same noise I am as his description perfectly matches what I hear also. Do you guys think it is normal to hear it sometimes? It is over an hour drive for me to the nearest dealership and I don't have a convenient time to go again in the next couple of weeks.

[IEDEI]

I get the same....it's normal in lots of turbo cars...especially when letting off the throttle

[Andrewcoja]

Originally Posted by roadcarver

It sounds like BAMA is having the exact same noise I am as his description perfectly matches what I hear also. Do you guys think it is normal to hear it sometimes? It is over an hour drive for me to the nearest dealership and I don't have a convenient time to go again in the next couple of weeks.

If you have the windows down and the radio off and you get over 3/4 throttle then let off and then hear a very quick whooshing sound, that is the blow off valve opening and releasing pressure from the turbo. This is normal and occurs on every car with a turbo. The reason why you sometimes don't hear it is because the the BOV on the N55 goes directly into the exhaust instead of into the engine bay like most turbos. You'll only hear it if you don't have any wind noise and only if you've built up a significant amount of boost. This faint noise has to make it from your tailpipe to your windows, so you won't always hear it, but trust me, it's there.

[PopsnBurbles]

I get this a lot. I'm pretty sure it's BOV or something of the sort. I get this noise when I have Sport Button on, then accelerate from 0-40 (not really WOT, more like 1/3-1/2 throttle) and let off the throttle. You'll get the noise when letting off the throttle and sometimes when the car shifts. My car is DCT. In highway/freeway speeds of 65+ the longer you have your foot on the throttle to gain/recover speed, the more likely the sound is made.

I think it's pretty cool considering it's the first FI car I've interacted with as a driver.

[rking117]

Originally Posted by titancrusher1

Its the blow off valve. If you think it needs to be checked have the dealership look at it

I am not convenced that this is the case. i have a 128 and under hard excelleration, during gear shifts i hear a whoose sound too. I am pretty sure mine is not turbo'd to have a BOV. I actually have been trying to fgure out what it is too. I will say that it does resemble a BOV sound but more quite.

[LAZ]

I seem to get a wierd soft howling sound but only when its raining. almost sounds like wind howling but its not my windows and again only howls while its raining outside...??

[titancrusher1]

Rking117 Go get your car checked out by your dealer. You should'nt leave it up to a forum or guess what it is. Leaks can be problematic

[roadcarver]

Thanks everyone for you input. I am not going to worry about it unless something changes and just have them look it over when I have them change my oil in a month or so. I am convinced it is the bov as some here have said.

[Bama335]

Originally Posted by roadcarver

Thanks everyone for you input. I am not going to worry about it unless something changes and just have them look it over when I have them change my oil in a month or so. I am convinced it is the bov as some here have said.

As expected, SA said it's the BOV.

1200 mile oil change is done, now it's time to really drive this thing!

[Eyeman]

I don't know if N55s make as many weird noises as N54s? My turbos were pretty quiet stock, but since I installed a DCI, etc, my cars has made all sorts of weird turbo noises. The most distinct noise you'll get is when you get the siren sound. Some say it is a sign of early turbo failure but mine seems to have gotten much better and I've had it for 3 or 4 yrs. Actually I don't really know if it's gotten better or if I've just gotten accustomed to it. You'll swear an ambulance is coming first few times you hear it. It's much more prevalent when the weather is cold.

[Huecifer]

This is going to sound insane, but I feel like I might bet this sound, too... it's like a very faint bird mixed with a laser. When I was really listening for it, I could swear it was coming from behind my left ear, so my best guess it has something to do with the seatbelt tensioner motor or something. It's like a little servo noise... strange, but because it's A: consistent, and B: the car is driving fine, I've just let it go.

PS: Trying to search for others with this problem on the forum was funny... what do you search? Chirping? Squeaking? You went with whooshing, which I would have never picked, haha