Boost leak?

[onceover]

I have no idea where its coming from in the engine bay, sounds like somewhere near the belts

but the strange thing is, when I press on the accelerator, the squealing goes away, I have read it could be a tensioner that needs some good ol' greasing up.

but since the ringing I am having a bad idle, and sometimes my idle would bounce up and down, or go up to 1100 rpm and as low as 700.

so is there a connection for my bad idle and the pitched noise, or do I just need to tune up my car.

and is it the pulley that's squealing?

[A4Shizl]

I'm guessing yoru timming belt is off by a few teeh. I would not drive the car if I were you.

[onceover]

okay, well now the car threw a CEL when i went to move it out of the driveway.

I hooked it up to my VAG-COM and got these codes:

16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 002 - Lower Limit Exceeded - Intermittent
16685 - Shareware Version. To Decode all DTCs
P0301 - 002 - Please Register/Activate - Intermittent
16686 - Shareware Version. To Decode all DTCs
P0302 - 002 - Please Register/Activate - Intermittent
16891 - Idle Control System RPM Higher than Expected.
P0507 - 001 - Upper Limit Exceeded - Intermittent
17519 - Shareware Version. To Decode all DTCs
P1111 - 002 - Please Register/Activate
16688 - Shareware Version. To Decode all DTCs
P0304 - 002 - Please Register/Activate - Intermittent
17658 - Fuel Level too Low
P1250 - 008 - Implausible Signal
16687 - Shareware Version. To Decode all DTCs
P0303 - 002 - Please Register/Activate - Intermittent
17519 - Oxygen (Lambda) Sensor Regulation: Bank 1: System too Lean
P1111 - 002 - Lower Limit Exceeded
16891 - Shareware Version. To Decode all DTCs
P0507 - 001 - Please Register/Activate

Thats an awful lot of fault codes. Wtf is happening!

[onceover]

so after clearing all my codes and going for a small drive, two codes reappeared.

17519 - Oxygen (Lambda) Sensor Regulation: Bank 1: System too Lean
P1111 - 002 - Lower Limit Exceeded

16891 - Idle Control System RPM Higher than Expected.
P0507 - 001 - Upper Limit Exceeded - Intermittent

also, there seems to be some sort of air leak coming from the thing circled in the image below:



could there be a boost leak or something? why would it be squealing?

[B6Lovin]

squealing = leaking air from valve.
leaking valve = boost leak
boost leak = bad idle

replace valve/fix leak and report back.

[onceover]

Sounds too easy!

The squealing has gone away since the car is cold. It only did that when i was driving home for about 25 minutes.

Sorry about being such a noob, but what valve is that? and how do i get it off, it has some strange clamps on it. Can i just break them free and replace them with hose clamps?

[nikkobdenis]

Thats just a breather valve. And yes just use a pair of snips and clip off the clamps and get some new hose clamps! Easy fix.

[onceover]

Alright. Another update

I did the boost leak test from a4mods.com and something is not working out for me.

I followed the directions exactly except i disconnected the PCV return hose from the TIP directly after the breather valve in the image above since i couldnt reach the hose clamp right on the intake hose.

When i pressurized the system, there was air coming from the dipstick hole and the other side of the hose i disconnected from the breather valve.

WTF?

[onceover]

got a photo to help you guys understand



So when i disconnect the breather valve, the green and pink, plug the green one, try to pressurize the system, air just comes out of the pink one.

When i plug that up, air comes out of the dip stick hole (blue)

When i plug all three or connect the pink and green and plug the blue, there seems to be some sort of air leak right behind the engine by the breather valve.

Is there something severely wrong here? As far as i know, the system should be completely air tight, or so say the DIY on a4mods...

[AgentHubcap]

Did you ever figure out what was going on here? I'm having similar issues...

[onceover]

supposedly its engine sludge, and i havnt been able to fix the problem yet.
i made another thread about engine sludge issues here: http://www.audizine.com/forum/showthread.php?t=222935

but im still at a loss as to what to do next.