I'm pretty sure the turbo is making a chattering noise it seems to follow the vacuum/boost gauge if you know what I mean, however I can't hear it anywhere through the stethoscope, the noise happens on cold starts and goes away after 30s to a min, and also happens at medium up to hard acceleration about 20kpa vacuum and I start to hear it. I do have videos but I can't figure out how to upload them from my phone, I guess I have 2 problems lol..

 

First , take off intake and check for shaft play, if that's ok, wiggle ur turbo and manifold heat sheild and see if they are loose

 

They make a noise when they're cold.

 

Thanks for the ideas guys

I did check for shaft play, there's none but there's seems to be end play, if push the spin the wheel it seems notchy... Otherwise it spins freely

I have removed one the heatshields, but there is one heatshield on the wastegate housing that's loose but there's no way it's making the noise I'm hearing, its not tinny noise, it's very loud and clicking noise I'd say, like super fast chirping metal on metal

 

if ur turbine wheel is notchy ur bearing could be bad. is there any way u can make a video of this noise

 

Yea all great ideas, but this one was obscure. After checking the obvious stuff like heat shields, bearing play in the turbo, free spinning wheel, timing chain tensioner, lifters, rockers... I was kinda getting frustrated by this, as if the car was winning this battle.


Ok update time. Being busy season haven't had a ton of time to diag the problem but today I had some extra time.

It seems like the problem is the turbo flange studs had backed off, like 1 thread each. Weird. Anyways I tightened them up hoping the gasket wasn't blown out but sadly it is lol. I'll be purchasing a new flange gasket manifold gasket and studs for both as well. I plan on inspecting the manifold as well once the turbo is out.

If I figure out how to post a video I will just for reference for people. I've never herd an exhaust leak sound so mechanical...

My thinking is this, when the engine was cold the turbo was loose enough that each pulse of exhaust pushed it away and it then rebounded back into the flange making a mechanical sound more then an exhaust leak sound. So loud you couldn't even hear the leak. Then as it heats up the metal expands quieting it right down to unnoticeable while at the same time revealing an exhaust leak sound on sharp quick revs only. Ya...

 

Might as well go big turbo now...