What is this weird chirping sound?

[RubyRed15]

You are using an after market wga so you need to know the preload of the spring for vacuum .. you need to do some researh on the subject now .

Oh, it's a 17psi spring.

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[Edkiefer]

Two places I would check, first make sure all connections from the turbo to TB are good.
Next, I would double check the DV value, maybe go to stock or even cap DV, just for a test to see if the sound goes away.
Last I would also datalog if TB is for whatever reason closing on you during the boost pull and note when it happens if close to sound period.

One note: If you do cap DV go slow on throttle both on and off as your not bypassing anymore (only do this for short test).

You need to try an isolate the noise through a process of elimination.

 

[RubyRed15]

Two places I would check, first make sure all connections from the turbo to TB are good.
Next, I would double check the DV value, maybe go to stock or even cap DV, just for a test to see if the sound goes away.
Last I would also datalog if TB is for whatever reason closing on you during the boost pull and note when it happens if close to sound period.

One note: If you do cap DV go slow on throttle both on and off as your not bypassing anymore (only do this for short test).

You need to try an isolate the noise through a process of elimination.

I have checked over all connections from airbox to TB at least three times - everything is tight and secure each time. I pulled, inspected, and reoiled the DV+ twice. The TB does close around the boost peak, but it does that even on the chirp-free tune revisions.

Maybe I'll try the stock BPV next; capping it seems like a bad idea.

 

[Edkiefer]

I have checked over all connections from airbox to TB at least three times - everything is tight and secure each time. I pulled, inspected, and reoiled the DV+ twice. The TB does close around the boost peak, but it does that even on the chirp-free tune revisions.

Maybe I'll try the stock BPV next; capping it seems like a bad idea.

If TB is closing at peak boost I can see that making the sound, generally, you only get the chirp when you let off of the throttle.
So the TB closing is because of TQ limiting in the tune?

Anyway, don't cap then (you could still, but don't) I would switch out to stock BPV and see if it goes away.

 

[RubyRed15]

I've been told the throttle closures are SOP for torque limiting. The chirps only happen under WOT - letting off is only happening in these clips because I was making sound clips... but maybe I misunderstand your comment, "generally, you only get the chirp when you let off of the throttle"?

I'll talk to the tuner about capping vs. Stock.

 

[Edkiefer]

I've been told the throttle closures are SOP for torque limiting. The chirps only happen under WOT - letting off is only happening in these clips because I was making sound clips... but maybe I misunderstand your comment, "generally, you only get the chirp when you let off of the throttle"?

I'll talk to the tuner about capping vs. Stock.

You're running the DV+ valve that can run with and w/o an added spring, if you are running spring maybe try w/o it.

My comment is that when boost is high and if TB closes fast, that can make the chirping sound, the BPV should migrate this issue as it's not good for the turbo.

See what your tuner says.

 

[RubyRed15]

Ok, I follow now. I'll do that.

 

[Rick B]

I haven't read all through this thread and I don't know if your an auto or manual. It sounds like a throwout bearing. If not some bearing in the turbo. I have heard that sound many times in the past it's almost always been a throw out bearing or a belt tensioner. What we really need is a sound recording near the engine under the hood and with the hood closed from the sides.

 

[TorqueMan]

I haven't read all through this thread and I don't know if your an auto or manual. It sounds like a throwout bearing. If not some bearing in the turbo. I have head that sound many times in the past it's almost always been a throw out bearing or a belt tensioner. What we really need is a sound recording near the engine under the hood and with the hood closed from the sides.

This is why I was asking if the sound only occurs at certain RPMs. It sounds like bearings to me too, but OP says it's associated with boost pressure rather than RPM. If it's bearing noise it should be tied to RPM.

 

[RubyRed15]

I haven't read all through this thread and I don't know if your an auto or manual. It sounds like a throwout bearing. If not some bearing in the turbo. I have head that sound many times in the past it's almost always been a throw out bearing or a belt tensioner. What we really need is a sound recording near the engine under the hood and with the hood closed from the sides.

Manual.

I'm not sure how I'd get a recording under the hood.

 

[RubyRed15]

This is why I was asking if the sound only occurs at certain RPMs. It sounds like bearings to me too, but OP says it's associated with boost pressure rather than RPM. If it's bearing noise it should be tied to RPM.

True. In the current, low boost tune, I can floor it at any rpm and it never chirps.

 

[TorqueMan]

True. In the current, low boost tune, I can floor it at any rpm and it never chirps.

This strongly suggests to me it's not bearings.

 

[RubyRed15]

So this is interesting... I did some additional testing on old tune revs known to chirp, including one that was tested less than a week ago, and which at that time sang like a canary, and today it chirped maybe only 1/4 of the time. The only thing different a few days ago was that it would have been 20-25 degrees cooler.​

 

[RubyRed15]

Today I discovered that the WGA hose barb is smaller than the factory size (totally didn't notice it when I installed it), so I can pull the hose right off, clamp and all. I tried rigging up a smaller hose, but even that won't get tight, and I can't find a smaller clamp anywhere. Tomorrow I'll look for hose with a thicker wall size.

I'm not sure if this is even an issue. Think it could be related?

 

[Gearhead82]

Today I discovered that the WGA hose barb is smaller than the factory size (totally didn't notice it when I installed it), so I can pull the hose right off, clamp and all. I tried rigging up a smaller hose, but even that won't get tight, and I can't find a smaller clamp anywhere. Tomorrow I'll look for hose with a thicker wall size.

I'm not sure if this is even an issue. Think it could be related?

Seems like if that hose was loose enough to be leaking air and causing your chirping noise, then it would have been loose enough to have just blown right off the barb at some point. Definitely worth fixing even if it’s not the cause though.

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