2003 E46 320d "Whooshing" sound

nemesus

New member
Hi all,

I am new to this forum and hope that someone can share their ideas on this topic. I tried the UK forum... uhm... :wrongforum:

Anyway, here goes:

There is a 'whooshing' noise from the engine area when changing up through the gears as I accelerate and momentarily lift off to select the next gear, or when I accelerate then back off. Have been told it's nothing to worry about as the noise is not getting worse, but again any advice would be gratefully received, if only to put my mind at rest.

About 2 months ago I changed my crank case oil breater to the new type (non-sponge), I cleaned my EGR and also removed my intercooler for a nice clean & presure test (Silverton Rads) before replacing it again

Ever since then (I might be imagening myself) I have this sound. It happens when the engine is hot or cold, boosting high or low. It only happens when the engine loses revs by depressing clutch or just back off on the throttle

It almost sounds like some vacuum of air going somewhere, or leaking somewhere.

If there are perhaps any newer updates on this behavior, please post a link to it - else, some ideas will help as well.

I am just concerned that prolonged use of the engine with this sound will cause damage to the engine
 

zaleonardz

Well-known member
Do you feel any loss of power from the turbo - ie turbo pipe leaks. ?

It could be as well that the PCV valve that you replaced was not installed correctly, and over time it is getting worse.
 

nemesus

New member
Nope, no performance loss... Still feels the same as always...

When you say PCV valve? Are you referring to the Crank Breather?
 

zaleonardz

Well-known member
Positive Crank Ventilation or PCV.. so yep.

If there is no loss of power then its prob not a boost leak which is really common.
 

Hellas

///Member
Mine has been doing that since forever and I've been told it's the turbo, but I like the sound

''WHOOOOOOOOSH!'' :)
 

nemesus

New member
I also thought it might be the crank breather - I actually removed it again, and replaced (re-fitted) it again just to be sure... No oil leaks in the breather's location, so all safe there.

I also suspect a boost leak - I emailed a couple of places (Steves etc.) and did not find anyone who can do a boost leak? All of them only do a dyno diagnostic test... Will this help or does anyone know of a place (pref in JHB) doing boost leak tests?

HELLAS said:
Mine has been doing that since forever and I've been told it's the turbo, but I like the sound

''WHOOOOOOOOSH!'' :)

LOL

For you it's ok because it has been doing that since forever... :)

But for me it's a worry as it was never there until about 3 months ago... :(
 

cfroc

BMW Car Club Member
This is only what I think or can think of with my limited knowledge on these modern technology!!!

It sounds as if it must be related to the turbo. When you lift off the excellerator, the turbo is still boosting and the excess pressure must go somewhere, that is why there is a dump valve, but I am really not sure if diesels have the same breathing setup as petrol engines.

It could be some leak in the system related to the dump valve, or maybe when you cleaned everything out, you made the whole intake system breathe better and it is maybe just a normal sound of everything working properly in sinc again, as Hellas said its been with his car since forever.
 

speeddemon

///Member
Nah you dont have to worry about it; it's quite common on the 320D's. I had a steptronic and it did the same and i loved it; especially when you accel and then take your foot off it.
I use to call it my blow off valve LOL.
 

nemesus

New member
also thought of that cfroc - it's the only thing that makes sense to me...

surely if the sound was an indication that the turbo is on it's way out, it should have popped already or at least increased the whoosh sound??

does anyone know a good machie that can check for such a leak at the wastegate? or of any shop in Jhb?

speeddemon - it still has the blow-off noise on the waste gate, the noise I have together with that sounds like a howling / whistling kind of noise...
 

STREETRACER

Active member
diesels run actuators coz a diiesel dont have vacuum like petrol engines to open or close a waste gate, that is why you cant put a dumpvale on a diesel! check your airbox pipes! if i remove my E90 320D air filter it does the same sound and loud! but i doubt its serious! if a turbo starts to fail you will feel los in power and it will smoke more than usuall!

Get it on a dyno! if they put ur car under load and on a external boost gauge they will be able to detect if it is loosing boost or if your actuator is a bit sticky!
 

Major

Active member
I'd say put it on a dyno just so you can be next to the car when you take your foot off to diagnose where it's coming from, otherwise it's guess work. Hell, it could be as simple as a leaking aircon pipe.
 

sash

///Member
walterso said:
nemesus said:
thanks guys :thumbsup: -- will book my car for a dyno diag at steves...

Hey how did it end up with the sound on your car, mine is doing the same thing.

With 12 Posts in 3 years I am not counting on you getting a response from the OP. Maybe others might shed some light.
 

ChefDJ

///Member
I have the exact same sound, and only sometimes :fencelook:

Happens when you accelerate, and then lift your foot off the accelerator slightly. As soon as you accelerate again, it disappears instantly, as if a valve is closing.
 

Nikhil

Honorary ///Member
ChefDJ said:
I have the exact same sound, and only sometimes :fencelook:

Happens when you accelerate, and then lift your foot off the accelerator slightly. As soon as you accelerate again, it disappears instantly, as if a valve is closing.

Mine does the same and has a new turbo :rollsmile: sounds awesome lol. and there is no loss of power either
 

ChefDJ

///Member
S1NGH 001 said:
You turbo housing is cracking :argh:

Nikhil said:
ChefDJ said:
I have the exact same sound, and only sometimes :fencelook:

Happens when you accelerate, and then lift your foot off the accelerator slightly. As soon as you accelerate again, it disappears instantly, as if a valve is closing.

Mine does the same and has a new turbo :rollsmile: sounds awesome lol. and there is no loss of power either


I don't see how it can be turbo housing if Nikhil has a brand new turbo, and it makes the same sound.

Doesn't bother me much. I don't really like the sound, so I just accelerate to make it go away :rollsmile:
 
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