Turbo making odd sound when warmed up

[Breezio69]

Ok guys, im kind of stumped here... I read through all the threads suggested by my title and still doesnt make sense.

My turbo is spooling a bit weird, but only when warmed up. I can only describe it as if you were whistling in to a fan... it.... flutters. I still hit full boost, still pulls strong. It just sounds odd, and its not all the time.

All of the threads suggested called for shaft play. Literally a week ago I had my entire intercooler piping and intake off the car to replace all of my couplers and t clamps. I also checked the turbo for shaft play while I was in there... I had ZERO shaft play. No up and down, no in and out. Its an Evo III GT, yes I know, garbage right. Well ive owned the car for 17k miles and I dont know how long it was on previous, so I guess with no shaft play even after 17k im thinking this turbo is an early one before all the bs went down with these turbos.

Im stumped, I dont know if I should worry about it or? Anything else to check is appreciated.

Also, when I pulled my intercooler piping there was just a tiny film of oil in the intake pipe. I dont know if this is blowout from the turbo or from the recirc line on the bov? It was barely enough to change the color of a rag.

Thanks all!

 

[JusMX141]

Sounds like a boost leak to me- probably at the j-pipe flange.

 

[WES_393]

I agree. It's a good idea to run a boost leak test anytime you mess with the charge pipes.

The oil in your inlet pipe is likely from the valve cover vent. A proper catch can setup would eliminate that.

 

[Breezio69]

Forgot to mention that I did do a blt, I also used a light mist of hairspray on my couplers and let them dry for a couple hours. I took a t clamp off and tried to move one of my upper couplers and that thing was stuck good.

The oil very well could be from my vc, didnt really put that together for some reason... But I am boost leak free with no shaft play. Thats why I dont even know where to start or assume its just normal, which I know its not being my 3rd turbocharged car.

Ill also note that somehow my j pipe inside bolt, left hand from front of car, stripped out. I drilled it out and installed a stud on the back side of the turbine housing facing forward. I also installed a new gasket with a tiny smear of rtv on both sides. The leak isnt there... or anywhere according to a blt.

In my testing I am currently running 13 psi. I want to run 20psi (hence new t clamps and couplers) and tested at 22 psi. Lost all air at around 23-24 seconds, tested 3 times.

This noise was also happening before and after my coupler install. Which I did have a boost leak before

 

[HIGHPSI4]

If it is a whistle then it is probably before the turbo. I have not seen any boost leaks whistle, their going to sound like escaping pressurized air unless it makes something vibrate.

 

[Breezio69]

If it is a whistle then it is probably before the turbo. I have not seen any boost leaks whistle, their going to sound like escaping pressurized air unless it makes something vibrate.

Its not a whistle though, its like a fluttering noise. Its really hard to describe. Im not sure if I can video it....

I was thinking maybe the wastegate wasnt staying 100% open and possibly partially closing (but not all the way because my boost doesnt change, creep, spike or drop..). But there are no leaks in the wg line.

 

[pauleyman]

Only when it's warmed up? Check for exhaust leaks.

 

[Breezio69]

Thats possible, I took a look at everything today and it appears where my dp meets the o2 housing it "pushed" the gasket out one side. Maybe it split and the vibration and exhaust pressure pushed it out one side a little? I felt around and didnt feel any exhaust though, and I had a new gasket installed there when I bought the car by a shop... it had an obnoxious pop sound when it was bad and doesnt do that now.

 

[Breezio69]

So I peaked around the bay again today and sure enough, the gasket from the o2 to down pipe is split in half and is hanging half way out the exhaust. The other day it was just barely out of line... today it is pretty much about to fall out

 

[pauleyman]

Tada!