screaching type whistle when building boost?

[mudygmc]

Hey guys we are having an issue with my dads truck. He was driving the other night and heard a pop sound like a back fire then the truck started screaching when building boost. That is what he told me so I don't exactly know what it sounded like. I drove the truck and it drives fine at low rpm's. At around 2600 when it starts to build boost. It makes a weird screaching type whistle. The truck is definetly not making boost. There is a majr loss in power. I thought it blew an IC boot but they all look fine. I was under the hood when he revd it up and the screaching seems to be coming from the back of the turbo. It looks like the smoke is coming from the bellow on the drivers side up-pipe. I blew the bellow on my pass side up-pipe and that just sounded like a hiss type air leak. It is an 05 lly. The vanes on the turbo cycle and there is plenty of oil there. I am looking for ideas.

 

[D-MAX Mafia]

Same thing happened to my uncles 05 turned out to be a warped exhaust manifold on the passenger side. We replaced it along with the gasket and problem solved. However, this was after we replaced the turbo and it continued to make the whistle. Hopefully its the same thing.

 

[BLKLMM]

exhaust leak , I would try to see behind turbo with a mirror or something:thumb:

 

[mudygmc]

Yeah it looks like an exhaust leak. The weird thing is he said it made a pop like a backfire. Would a gasket or bellow pop? My bellow that I blew just started hissing and blowing black smoke out from under the hood. It looks to be the drivers side up-pipe. It can never be the easy side. I think I will pick up a set of gaskets and swap my old up-pipe in and see what happens.

 

[SgtKilroy]

If the elbow pops out of your Y bridge it makes a similar sound.

 

[hondarider552]

I think the drivers side up pipe is way easier to get out than the passengers..

 

[DIESELMAFIAPER.LB7]

I think the drivers side up pipe is way easier to get out than the passengers..

Your carzy I can't hardly get my arms in there for that one passenger side just take dp off an its easy drivers side sucks

 

[D-MAX Mafia]

x2 passenger side is easier.

 

[bunkerkid06]

If you were to not have one of the bolts in driver side up pipe, more specifically the bottom bolt, it would make that screeching sound correct? I broke the bolt off and I swear this bolt was forged in the fires of hell, we tried torching it out and all it did was catch fire and then nothing, tried getting it hot and then punching it out, nothing, finally got a dremel and about 100 stones later we finally gut it out, now I have a stud in it and no nut to fit it, I torqued the other 2 top bolts tight and my truck makes the same screeching sound, now I understand that it is more than likely the stud with no nut on it but is there absolutely anything else that could make it make this sound? Please pm me or post to here and I will try to find this post again, but it's probably easier to pm me thanks all

 

[Hot COCOAL]

Hold your finger above/on the broken stud while the truck is idling, it's ok, it's hot so don't go pressing and holding your finger there, just lightly hold it over the hole, you'll know what's what real quick as your finger will block the noise when it covers the hole/stud

:thumb:

 

[NC-smokinlmm]

The metal gaskets make a terrible sound when not compressed properly, think of a reed with air moving across its flat surface. I had one that had a hole burnt thru it and it sounded like bearing squeal. I am willing to bet it has a hole burned thru it where it wasn't fully compressed...