04 s4 whine noise near intake pipe

[safi24]

Hello, new to the forums here.

A couple days ago my 2004 s4 (b6) has a whining noise that is always on and coming from one of the hoses near the intake pipe.

The noise is always there now since a couple days ago, it used to be every once in a while. The noise doesnt start when the car is switched to ON position, but the noise comes on and stays on at all times as soon as the car starts. Noise goes away completely after the car is turned off.

I have pasted a link to a video i posted on youtube of the hose that is making the noise. Maybe the hose has a leak in it? The hose is also vibrating from the noise.

Car:

2004 s4
4.2L v8
6 speed manual
No check engine light, but was misfiring and CEL came on for a day, then went away. (Happened a week ago)
110xxx miles
Air filter is clean
Only mod is catback exhaust
Will need an oil change soon
All fluid levels are good/at maximum

VIDEO:
https://youtu.be/1ekdNXXjn3Q

I searched and couldnt find anything any help would be appreciated. Thanks

[Terry.Reese]

all hoses seated correctly and tight?

[kevinye77137]

Im putting my money on the failing secondary air injection

[alcatranz518]

I second the (no pun intended lol) the Secondary Air Injection Pump is starting to go. Its located below the air intake system. Mine will whine at startup on a rare occasion like I got a lil boost action goin on, but then it subsides for a few months again thankfully.

You should kick an engine light when it goes. The pump can be expensive, but JHM sells block off plates for the ports and can shut that node off in their tune so you have options.

[AllroadMass]

Secondary air pump should shut off around 45 seconds after you start the car. From what I understand, It runs at the start to pump air and get the cat up to temp. So I'm not sure why you're hearing it all the time. Replaced mine last month not too bad.

Sent from my Nexus 5 using Tapatalk

[safi24]

Thanks guys, i appreciate the quick feedback. I'll look into the secondary air injection pump.

I looked on youtube for the sound that part makes if it goes bad, and search results sounded different from the sound i have.

I will also check to male sure all the hoses are connected properly with good fittings amd clamps etc.

If you all have any other ideas, please let me know.

Thanks.

-Safi

[TarlCabot]

the infamous PCV ....

you can see it here top center... lil bit of a pita to replace because they stick and the factory one-use clamps



if secondary air, then it would only be on for cold starts and shut off after a few minutes

[TarlCabot]

Another pic, black round piece with hose still attached... top center rear of engine




squirt a little bit of wd-40 on it and see if tone changes

[safi24]

Makes sense, thanks so much TarlCabot.