So, I tried to record a video of it, but no success - I will try to describe it best I can.

2006 Evo IX MR

So.. When I accelerate rapidly - mainly seems to happen in the lower gears (because I approach redline quicker?) - when I get on the gas hard (not necessarily WOT, but for argument's sake, let's say it is WOT).
From 1-4k rpm, all is fine, then 4k+ all the way to red line there is a higher pitched hiss.. almost as if there was an air leak, BUT when I look at my boost gauge I maintain 17-19psi boost.

As I mentioned it happens easily in 1-3, then 4-6 it's a little harder to get it to happen, but still does.

That is the best I can describe it, I bought my car used @ 65k Miles, I now have almost 75k. I bought an external power train warranty, which the turbo is included under, I just dont want to pay the dealership $100 to figure it out if I can at least go to them and sound like I know what I'm talking about.

Any/All help is appreciated, Thanks in advance.


Edit: I guess in title it's a boost issue.. not specifically the turbo.

 

Maybe you have an exhaust leak instead? Check your gaskets! I dont know what to say if it's not some sort of leak. Good luck with the problem

 

Boost leak, or malfunctioning blow off valve is my first thought.

 

Thanks guys.. my friend's dad who works on cards (but not super experienced with turbos) suggested, maybe the waste gate (actuator) (?) possibly?

I was thinking.. if there is a leak in any of the silicone connectors.. but I don't see a drop in boost pressure, or the BOV as well, but.. I'm inclined to say the same thing.. unless it's small enough to make an abnormal noise, but not to drop pressure.


I didn't even think exhaust leak, but I'll definitely keep that in mind.

 

I got almost same problem as yours, it's wastegate. Mine oem one had bad spring, I end up to get new one and problem gone

 

You won't see a noticeable drop in boost pressure. The turbo works harder to maintain boost pressure. A boost leak test should show if you indeed have a leak(s).

 

Had similar problem, but mine was pouring out of the throttle body.

 

Good to know someone has experienced almost exactly what it is. Thank you.


I also went to the hardware store and bought what I needed for an at-home DIY boost leak piece. I will hopefully be able to do that this coming week to check.

 

Also, I was able to try again and get the sound. I was on the freeway, I couldn't go from idle to red line.

But here is a link to it, it's that high pitched whistle you can hear.
https://www.dropbox.com/s/igjkx5eg3n0t881/IMG_1025.MOV

If there are any problems accessing it, let me know, and I will upload to youtube or something.

 

granted I have a different engine (4g63) than you, my car sounded similar when I had an exhaust leak. It got nicknamed "the banshee" over the 3 days before I got a chance to fix it. For me it was leaking out from the manifold to turbo gasket as the bolts were a little loose. If anything on the exhaust had been taken apart, I'd check that area first.

 

Little update in case it helps feed the brains of you guys that might know.

I went and made a DIY boost leak tester like I mentioned, between yesterday/this morning I went and performed a boost leak, it seemed to be coming from the intake manifold.

Again - if you have trouble seeing the videos, let me know - I can upload elsewhere.

https://www.dropbox.com/s/06ag8o7y6g...%2023%20AM.mov

https://www.dropbox.com/s/2i9a8w4loy...%2033%20AM.mov

 

I should also note, a lot of the DIY boost leak test posts recommend ~20psi in the system, it wouldn't hold 20.

 

I didn't watch the videos, but just from that picture I can see that your injector seals are leaking. They're the rubber donut seals that go between the injectors and the intake manifold. Replace all of them along with the o-rings that go between the injectors and the fuel rail. I've had to replace mine once already, it's not difficult. Note: be careful when removing the small metal clips on the injector connectors. They're not available for purchase individually; you have to buy the entire wiring harness.
Other areas worth checking are:
- throttle body shaft seals
- vacuum lines that go to the intake manifold & EGR system (several small rubber hose connections behind the intake manifold)
- blowoff/diverter valve. I had a stock IX valve that leaked at 22psi.
- intercooler hose connections
- pcv valve

 

Most likely you have multiple leaks, but from the photo, your injector seals are in need of replacing. STM sells those and the oring to the rail. I wouldn't keep pushing your turbo until you fix all the leaks, but start with the injectors first. Have you replaced the TB seals? Most likely those are leaking as well. If your on a stock WG, you might want to replace that with a 18psi from FP and re-tune.

 

Hey, Syringe give me a call at 585-226-8226, we should be able to figure out your issue and get you the parts you need!
-Ethan