View Full Version : What is this damn noise?!?!
audisarecool
03-22-2007, 10:57 PM
alittle over a week ago i was getting a carwash, im not sure if this is related but only after the carwash did i start hearing the noise...
at first it was a very slight whistle that ied hear when driving normally between 0-40 mph...any faster and the wind muffled it...
...i felt no power loss...over the past week its been the same, if A/C is on u can barely hear it...
...so today i get my carbonio cai installed and as i pull out of the shop i hear the whistling louder than ever before, im almost positive im feeling powerloss and the intake does not sound smooth at all. almost as if there is blockage in there or something...keep in mind this is a shop that installs these on a regular basis so they are experienced...
anyone experience anything like this? im 100% sure its not the squeel of the turbo at redline, its a distinctly different sound
...my initial thought is obviously a boost leak and i have an appointment at audi on monday to have this checked out, hopefully its nothing serious... only "go" mods are apr 93/stock and carbonio intake
...i will try and not drive the car till i bring it in to avoid any further damage...
B7AudiA4
03-23-2007, 12:46 AM
Maybe Diverter Valve?
or maybe the boost leak.[up] But I doubt the dealer would help you.
denisk
03-23-2007, 10:30 AM
Does it sound like a blow off valve? Like its sucking in air? Cuz if it is thats normal. Intakes usually do that. Although I cant explain the power loss that your feeling.
audisarecool
03-23-2007, 10:41 AM
well my service guy was quick to suspect i have a "vacuum leak or something" an that they could take care of that so i hope they will be able to help...
and it does make the whoosh sound sort of like a blowof valve but this noise seems to be coming from a differen part,
...when i push the car hard and the intake just its whooshing, toward redline the whooshing dies down but if u listen to the engine you can still hear the whistling continue as long as my foot is planted.
this leads me to believe that its got to do with my car boosting...
Pure Euro
03-23-2007, 10:50 AM
Most likely a blown DV.
audisarecool
03-23-2007, 12:09 PM
oh yea and i forgot to mention, theres no CEL showing...
audisarecool
03-25-2007, 06:51 PM
nooone has any idea?
some added information, when im rolling and in neutral and rev the engine, the whistling isnt there and the intake sounds exactly like its suppose to...
but when in gear, the nastly howling at all speeds and rpms continues and the "bov" like sound (those who've heard a carbonio know what i am referring to) at the end is all over the place instead of a nice solid "whoosh"...
this leads me to believe that its related to boost since im pretty sure the car doesnt boost wihle in neutral (auto trans)...
any thoughts?
nooone has any idea?
some added information, when im rolling and in neutral and rev the engine, the whistling isnt there and the intake sounds exactly like its suppose to...
but when in gear, the nastly howling at all speeds and rpms continues and the "bov" like sound (those who've heard a carbonio know what i am referring to) at the end is all over the place instead of a nice solid "whoosh"...
this leads me to believe that its related to boost since im pretty sure the car doesnt boost wihle in neutral (auto trans)...
any thoughts?
When you place your car in gear, the engine will have a load, and boost is created. The noise you hear is probably a combination of a blown diverter valve blowing boost back into the turbo inlet pipe and it's amplified because the carbonio intake is more free flowing and the sound becomes more to the forefront.
When you rev the motor while in neutral, you're not putting any load on the motor, therefore not making any boost. So any boost leak or diverter valve failure is not obvious because due to the fact that you're not making boost which means there can't be any boost leak.
When you place your car in gear, the engine will have a load, and boost is created. The noise you hear is probably a combination of a blown diverter valve blowing boost back into the turbo inlet pipe and it's amplified because the carbonio intake is more free flowing and the sound becomes more to the forefront.
When you rev the motor while in neutral, you're not putting any load on the motor, therefore not making any boost. So any boost leak or diverter valve failure is not obvious because due to the fact that you're not making boost which means there can't be any boost leak.
yep, he's right. its definitely boost related. it does sound like a blown dv to me, or at least the hoses that go to the dv. When you say its "uneven" when letting off the throttle instead of a smooth "swoosh," is it a sputtering or fluttering sound?
audisarecool
03-29-2007, 07:16 AM
"fluttering" is the best way to put it...
update - got the car back from the dealership and they told me it was NOT a boost leak, wether or not they checked is beyond me since the problem still exists...
they claim the whistling was coming from a lack of good fitment in the "acordian(sp?)" type plastic thing in the picture below...
http://i49.photobucket.com/albums/f263/nytrackstar/intake_carbonio_b7a4.jpg
they said they when they re-alligned it the whistling went away...
problems:
-they serviced the car in stock mode, in stock mode the noise was barely audible in the first place...
-when first driving away i heard an improvement in the sound for a little while, it gets worse everyday
-i taped up almost all possible "cracks" where wind could whoosh in from and there was little to no improvement in sound...
-i havent tested the noise while the car is stock so im not sure if they got worse as well
...the shop that installed it had to shave down some of the sides to help fitment, they used a dremel type tool on the edge around where the screws are(behind the edge on the top of the above picture)... could this be an issue?
...anyone in the syracuse (13210) are wanna help me work this out? lunch,beers on me ofcourse haha...
...ill try and take some pictures for you guys today if i can...
ps - do u guys think the dealer has a fool proof way of checking for a boost leak? or is it likely they didnt do a thorough enough test...
ps2 - can someone please explain to me how the following relate to another in the following situations on a TIP tranny car:
1. boost
2. air into the intake
3. whether or not im in gear
...what is the whooshing sound from? air being sucked into the CAI? does this happen only when moviing?
...because when in neutral and rolling i can hear the intake make the exact noise it is suppose to, it does not make this when in neutral and stopped...
...does the car "actively" suck air in or is it caused by the movement of the car? does whether or not im in gear effect how much air the engine will suck in? ...does the spinning of the turbo create the vacuum that sucks in air?
...i kno i have a lot of questions but im tryin to figure this issue out...
...if the whistling were coming from a crack, is there any reason it wouldnt happen when im rolling and revving the engine while in neutral?
i appreciate all this help!
ps3 - should i bitch to this shop about modifying my intake to make it fit instead of taking the time to fiddle with it and make sure it wont fit... i dont think modification should have been their first move without asking me... any opinions on this are welcome as well
THANK YOU!!
audisarecool
03-29-2007, 11:26 AM
i kno somebody can help me! cmon guys, rally together now!
4-tified
03-29-2007, 12:09 PM
i kno somebody can help me! cmon guys, rally together now!
This type of thing is VERY difficult to ascertain over the internet, nearly impossible.
People can only offer suggestions and guesses, especially on something like this.
First, the stock DV in this engine is BARELY audible if at all. It's not a BOV, and by it's design, it is inherently quiet.
It is unlikely that you are hearing it all, even if it were bad or had a tear in it, you still probably wouldn't hear it.
Now, in the intake there can be sound. Many cars have this minor issue where the air rushing over and around the throttle plate can be heard by some people.
In certain throttle angles it could be louder.
It may even sound like a vacuum leak, which is typically a very high pitched steady squeal.
Why would this sound be louder with the new intake?
Probably because most aftermarket systems are designed to allow the normal intake sound to become louder. Many enthusiasts like the louder intake.
So, the sound that was already there is simply more audible now.
In neutral and at idle the air coming in through the intake is less and the throttle plate angle is different, thus you may not be hearing it, and it might not be there at that angle and air volume.
With the added boost the intake air is denser and that can easily change the sound even at the same throttle angles.
Try this, go about 55mph in 3rd, then use 5th, and 6th, but maintain that speed.
You'll be changing the angle of the throttle plate.
Is there a change in the sound you hear?
Also, try 55mph in 6th and then go full throttle and listen if that sounds changes or goes away.
At this point, you're probably overly "tuned in" to that sound.
Based on your writing, it sounds like you might be.
I've done that myself. You concentrate on it so much and it becomes even louder.
Try having some other A4 turbo owners drive your car and don't tell them what you hear, just ask if they hear anything different than their A4's.
You could also go to the Audi dealer and try some other 2.0 A4's and listen to how they perform
Keep up posted.
A4_Eyez
12-07-2009, 07:24 PM
I have the same sound, when I let off the throttle it makes this swoosh sound. While I am in gear only though; I've tried it in neutral and did not make the noise. I am going to the dealer tomorrow try to keep you guys posted.