What is this weird chirping sound?

[Marvinmadman]

Boost leak maybe?

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[RubyRed15]

Maybe. I have a boost leak test adapter on the way, but I really don't think that's it.

 

[Edkiefer]

you dun fucked that engine !

I am curious what noise you are hearing that gives you that impression?

This is why recordings are a bad way to test things, but I guess next best to being there, not much you can do really.
Since the recording was from under the hood, things I can pick out are.
Direct injection injectors (clicking noise), Turbo spooling (turbo whine) and the DV+.

Being everything is so exaggerated in volume, the turbo whine is what bothers me the most, but again everything is loud.

 

[RubyRed15]

What bothers you about the turbine whine?

 

[TorqueMan]

Another weird noise that I always assumed was just strangeness from the DV+, but I'm not so sure anymore. Especially in 3rd and 4th, listen for the gravelly sort of sucking sound that builds up into the squeak of the DV+ opening. This video is from underhood.

What do you think? Normal? Boost leak? Something else?

Consider recording both under the hood and in the cabin at the same time, using video in the cabin. Sync up video of the boost gauge with audio from under the hood.

That said, I don't think you can find a boost leak with a microphone. The gravely noise you're hearing sounds like typical air induction noises to me. Air flowing through the induction system can make noises even if there isn't a leak, especially with all the plastic. Any place in the intake tract where the air changes direction will introduce turbulence in the flow, which makes noise. If your mic is near such a spot it will pick the sound up.

 

[RubyRed15]

Well my cell phone was duct taped to the first bend in the hot side charge pipe, so...

It is audible in the car, too.

 

[Edkiefer]

What bothers you about the turbine whine?

well, it kind of loud whine.
When turbo bearings go bad the turbo will make a louder whine, but also the pitch changes with load.
What is happening is the shaft it touching the housing side on the intake side.
I am not saying this is happening, it is just something to keep eye on in general.

I used to check this w/o taking apart turbo, you have to remove intake pipe and carefully with your index finger check for first play front to back (there should be no play here).
Then gently with only your, fingers move intake impeller side to side. Here you should have play but it should not touch the housing. This is just a quick test and not a definitive test.

A few posts up you asked about WGA pressure, what lb# are you running now and I assume you preloaded it when it was installed?

PS: I listened last night and I didn't think anything bad, but like I said I hate trying to figure problems from recordings.

 

[RubyRed15]

I tried that movement test when that siren noise first began but I could not detect any movement in any direction. I also replaced the stock charge pipe and intake tube, but neither had an effect on that noise, which is loud at cold start.

Current WGA is the Borg Warner unit Vargas sells as an upgrade. It has 2mm preload and rated 17.6 psi crack pressure. I tested with the boost controller unplugged, and it allowed a ~19 psi spike before settling at ~16.6 psi.

 

[Edkiefer]

I tried that movement test when that siren noise first began but I could not detect any movement in any direction. I also replaced the stock charge pipe and intake tube, but neither had an effect on that noise, which is loud at cold start.

Current WGA is the Borg Warner unit Vargas sells as an upgrade. It has 2mm preload and rated 17.6 psi crack pressure. I tested with the boost controller unplugged, and it allowed a ~19 psi spike before settling at ~16.6 psi.

Ok, well that is good.
Are you running upgraded turbo, not that it matters much.
With that WGA lb# whats your tune target boost set to and what is your running boost.
Those chirps could be totally normal if there not much delta between WGA and actual running boost.
What I am getting at is ECU can't lower boost (to limit TQ), below WGA numbers so some noises will happen IMO.

I would focus on what your tuner says, he's got best inside look at whats going on.

 

[RubyRed15]

Chirps happen with a 24psi midrange target, which typically spikes at 25-26 psi at the end of spool-up. I am now lowered to 21 psi to avoid the chirp. Stock turbo.

 

[RubyRed15]

I used to check this w/o taking apart turbo, you have to remove intake pipe and carefully with your index finger check for first play front to back (there should be no play here).
Then gently with only your, fingers move intake impeller side to side. Here you should have play but it should not touch the housing. This is just a quick test and not a definitive test.

Just tried this again... still can't feel any play, axial or radial.

 

[Edkiefer]

Just tried this again... still can't feel any play, axial or radial.

That is good, generally you will have slight play radially, cause of the oil cushioning in the bearing (inner/outer), so from what your reporting only thing that comes to my mind is your hitting a TQ limit on that 25-26lb boost and only way the ECU can reduce TQ is by throttle limit (can reduce boost only to WGA pressure).

That is just a guess I don't have a lot of experience with new 2.3 EB's tuning wise.

 

[RubyRed15]

UPDATE: The chirping noise was open throttle compressor surge, and the siren noise was a failing turbo bearing. After hearing the turbine blades zipping against the inside of the housing, I pulled the intake off and felt obvious radial play. Turbo replaced at 27kmi.

 

[Edkiefer]

UPDATE: The chirping noise was open throttle compressor surge, and the siren noise was a failing turbo bearing. After hearing the turbine blades zipping against the inside of the housing, I pulled the intake off and felt obvious radial play. Turbo replaced at 27kmi.

Glad you finally found the problem, to bad it was the turbo.
If your going to run stock turbo try and maybe keep it under 24lb, the high boost maybe causing overspeed of turbo.

 

[RubyRed15]

More to the point, if you hear a chirping noise from under the hood when tuning the car, stop immediately.

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