Blown turbo lly?

[Wyatt.bilodeau]

Hi all, I was wondering if anyone has some knowledge about the lly duramax turbos? I just did head gaskets and studs in my lly, changed the y bridge and intake manifolds out for lbz ones (because they’re bigger) and after driving it around for a few miles I’ve noticed this like howl noise from the turbo. I do know this is supposed to happen normally on let off, but my howl just doesn’t sound right and I’ve noticed it while I accelerate in low rpm as well. I’ve attached a video with two clips where you can hear the noise. In the second clip you can kind of hear the howlish sound while accelerating. If anyone has any ideas that would be super appreciated thanks!

Source: https://youtube.com/shorts/J6uV0jKv590?feature=share

 

[2004LB7]

Does it do it when not under a load like revving in neutral?

 

[Wyatt.bilodeau]

Does it do it when not under a load like revving in neutral?

Nope not at all in neutral

 

[1FastBrick]

Intresting.... Sounds like the turbo or something with the intake track to me.

 

[2004LB7]

I'm thinking some on the intake too. Maybe a rag in the turbo pipe?

 

[Wyatt.bilodeau]

I'm thinking some on the intake too. Maybe a rag in the turbo pipe?

No rag or anything, I thought maybe the filter was clogged or something but I took that off and ran it and still made the same noise. The intake is pretty small though, it’s a cold air intake for an lly and I put an lbz mouthpiece on so the intake is kind of rigged on until my new intake comes in but no restrictions that I can see.

 

[Nate’s Dmax]

For a few bucks you can buy adapters made to pressurize your system and see if you have a leak anywhere.

 

[BrandonLLY]

Is it building normal boost? If not could be boost leak, and if so, could be exhaust leak.


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[Wyatt.bilodeau]

Is it building normal boost? If not could be boost leak, and if so, could be exhaust leak.


Sent from my iPhone using Tapatalk

Yes seems to be building pretty normal boost, I just recently installed the boost gauge while I had the motor out so I’m not sure exact numbers but now it’s right around 20 - 25 psi

 

[1FastBrick]

No rag or anything, I thought maybe the filter was clogged or something but I took that off and ran it and still made the same noise. The intake is pretty small though, it’s a cold air intake for an lly and I put an lbz mouthpiece on so the intake is kind of rigged on until my new intake comes in but no restrictions that I can see.

This could be the restriction causing the noise.

Hopefully you get the new intake in soon and you can see if it changes.

 

[Wyatt.bilodeau]

This could be the restriction causing the noise.

Hopefully you get the new intake in soon and you can see if it changes.

Well I got the new intake installed and put a few miles on it, unfortunately the noise is still there. Could it be a wastegate related issue?

 

[Nate’s Dmax]

The LLY doesn’t have a wast gate as it is variable vane. Did you use the factory LBZ Y-bridge or is it a custom piece?

 

[Wyatt.bilodeau]

The LLY doesn’t have a wast gate as it is variable vane. Did you use the factory LBZ Y-bridge or is it a custom piece?

Oh right it’s an electronic solenoid right? And its factory lbz intake manifolds and y bridge. I was thinking it was something along the lines of those pieces being different size, but I heard the noise before I put those on. Quieter, but still heard it

 

[Bdsankey]

The LBZ pieces (bridge/intake clams) are bigger but it's minor. Guys have made deep into double digits with the OEM LLY clamshells.

Is it a stock turbocharger? How crazy is your tuner getting on vane position?

 

[Wyatt.bilodeau]

The LBZ pieces (bridge/intake clams) are bigger but it's minor. Guys have made deep into double digits with the OEM LLY clamshells.

Is it a stock turbocharger? How crazy is your tuner getting on vane position?

Turbocharger is 100% stock with 122k miles on it, definitely been very hot a time or two and I am running a ppe economy tuner which is about a 120 hp gain but im not entirely sure the vane position

 

[Bdsankey]

Turbocharger is 100% stock with 122k miles on it, definitely been very hot a time or two and I am running a ppe economy tuner which is about a 120 hp gain but im not entirely sure the vane position

Put the truck back to stock and see if the noise goes away.

As for vane position, a decent scanner would tell you that data.

 

[Wyatt.bilodeau]

Put the truck back to stock and see if the noise goes away.

As for vane position, a decent scanner would tell you that data.

Okay, I will update once I do that after work

 

[Nate’s Dmax]

Do what Brad said but i would also suspect maybe a hole in the charge cooler system be it boots, pipes, or inter cooler.

 

[Nate’s Dmax]

Oh right it’s an electronic solenoid right? And its factory lbz intake manifolds and y bridge. I was thinking it was something along the lines of those pieces being different size, but I heard the noise before I put those on. Quieter, but still heard it

I was gonna say that it might be the LBZ y-bridge coming apart but since it was doing it before it probably is somewhere else. Don’t rule out an exhaust leak either.

 

[Bdsankey]

Build or buy a boost leak tester if you suspect a charge air side leak, you will save yourself so many headaches.