[Alan l.]

I just started noticing this last week after i topped off some oil on my 335. It sounds like a faint ship horn type sound (or my car is farting lol) but very low volume that you can only hear if you are outside near the hood. With the hood open it sounds like it coming from the near the header/coilpack side. The sound isn't always there...I would say every couple of minutes i would hear it go off for 1-2 seconds and stop...then repeat again a couple of minutes later. You do not hear this from inside of the car and everything feels perfect. I also seem to only notice it when the car is fully warmed up and not during cold starts. The car only has about 9K miles on it. What could it be?

Sounds like my car is passing gas

Alan

[enrita]

[themyst]

Bad dvs would be my guess

[Alan l.]

Originally Posted by themyst

Bad dvs would be my guess

But the dvs are on the driverside of the motor. this sound is def. more towards the passenger side and only hear it during idling when warmed up. It sounds like some type of pressure value opening up every couple of minutes.

[Kevin@AKMotorwerk]

Originally Posted by Alan l.

But the dvs are on the driverside of the motor. this sound is def. more towards the passenger side and only hear it during idling when warmed up. It sounds like some type of pressure value opening up every couple of minutes.

stupid question, but did you make sure you closed your oil fill cap tightly? if its open or not sealed it will make similar sounds

[themyst]

Only reason I made that guess is bc bad dvs/bov will make a turkey gobble noise which could be construed as a farting noise. . Just an uneducated guess!

[Alan l.]

^^ yeah i did. at first when i heard it the cap was open because i was topping off my oil but still hear it after i closed the cap.

[shiv@vishnu]

At least it's not silent but deadly

[cn555ic]

Alan my car did that since day one! It sounds like pressure releasing and like a girl trying to let one out quietly! lol It does it after the car is warmed and when you are under the hood! Normal to me

[shifterboy45]

sounds like you may have a abnormally loud crankcase seperator valve -- on N/A cars its called a cyclone seperator..

sounds like a little tugboat in the harbor..... kinda annoying after you laugh for awhile..

[Jeff@TopGearSolutions]

Originally Posted by cn555ic

Alan my car did that since day one! It sounds like pressure releasing and like a girl trying to let one out quietly! lol It does it after the car is warmed and when you are under the hood! Normal to me

Girls dont fart or poop, dont ya know.

[Stangorang]

Sounds like you are describing the same thing as this guy: http://www.e90post.com/forums/showth...ghlight=hungry

He never posted a followup though.

[Alan l.]

Sounds just like the video but mine isn't non stop like his. I hear it for 1-2 seconds and it stops....then a few minutes later i hear it again.

[shifterboy45]

do a quick search on cyclone seperator noise on the web -- youll find that its pretty common -- there are even vids which you can compare the noise youre hearing to others --

or you can feed or engine and burp it if that works

[Kevin@AKMotorwerk]

did you check if your coolant tank cap was closed right and the bleeder nipple next to it is tight? that would make a gargling "fart" sound once warmed up and the antifreeze is moving around in there

[Alan l.]

thanks for the info guys.

Kevin - now that you mentioned it i did notice there are some residue around the bleeder nipple on the coolant tank last week. I'll check it tonight to make sure that it is tight.

Worst case i'll give my car some Gas-X in the morning lol

Alan

[EastBayE90]

I also have a similar noise but I mostly hear it at idle while sitting in the car when its warming up. It's like you describe a drone type hummm that sounds like a fart and it pulses for a few seconds and goes away. Then a min or so later it comes back. I only notice at warm up idle. I've never heard it after the motor gets really warm. My e90 has 44,000 miles and it has been making this noise since the day I bought it in September with 39,000 miles on it. And it makes it with the procede in or with it out it makes no difference. I just assume its another one of the mysterious N54 noises and I gave up on trying to understand it until I saw this post. Would be interesting to find out what is the cause of the noise.

[WilliamE92]

mine does it too

not sure what it is, but its coming from the same location as the noise in the vid

[cn555ic]

Alan...I heard it on at least 4 other cars that I installed the Procede...Its normal but if you ask me where its coming from I would say somewhere near the DVs or manifold area...It seems to bleed air out which sounds like a fart with butt cheeks squeezed together in order to hide ones fart escapades!

[Kevin@AKMotorwerk]

Originally Posted by cn555ic

Alan...I heard it on at least 4 other cars that I installed the Procede...Its normal but if you ask me where its coming from I would say somewhere near the DVs or manifold area...It seems to bleed air out which sounds like a fart with butt cheeks squeezed together in order to hide ones fart escapades!

thanks steven, i needed that laugh

[shifterboy45]

maybe the mystery of this is due to lack of information??

if you feel inclined to read the pages in the .pdf file -- 11-13 will explain the operation/purpose and location of the cyclone seperator.

its pretty simple once you know what the engine is doing, rather than just guessing.

crankcase ventilation hasnt changed since the inception of the engine -- so the 2007 data still applies.

cheers!!

[EastBayE90]

Good knowledge shifterboy the mysterious farting sound has been explained.