Hello ladies and Gents, so I've been having a troublesome problem these last couple of weeks. A dreaded boost leak has been haunting me. Let me start by giving a little background info. Car has a 1jz with a driftmotion single kit, safc2, and some other supporting mods. Car was previously running on 16 lbs successfully with no problems. I parked the car and it sat overnight, went to drive it in the AM and car was only boosting to 7psi. So I automatically checked vacuum lines, and couplers first. Everything was fine so I looked to the wastegate (deltagate mk2, was on the car when bought). Took it off gasket was broken/burnt so I ordered a new one. Took the wastegate apart and all looked well. Replaced the gasket and re installed the gate. Car started boosting to 9-11 psi. So I proceeded to check the BOV (hks ssq). The bov spun in the flange easily. So I got a new O-ring and c clamp and that fixed that problem. Car was still boosting the same, but now I am getting a whine from what sounds like the turbo (looks like turbo from cx racing). I have done some research and signs are pointing to my turbo going bad/ Is. I have been shopping for a new turbo these last couple of weeks anyway to upgrade, but I would just like to get some input from some of you all if that is possible. I do plan on replacing the wastegate with a Tial 44mm when I do the turbo as well. My question is, What are the chances of the turbo causing the leak? Any input of any kind would be greatly appreciated, Thanks in advance!

 

Is the WG leaking off boost, not closing fully until the spring pressure is reached does it have a fire ring not familiar with that gate? are the front and rear housing tight to the cartridge?
I'm not familiar with DM turbo's does it have a large O ring at the front cover to Back plate?

Is the turbo smoking on start up or under boost IE: bad seal or worn bearing.

Manifold bolts tight? flange to turbo gasket burnt or leaking from loose bolts.
I personally have never seen a turbo start loosing boost if it its on its way out it usually just runs till it fails.
GL. LMK.

 

Wastegate does not have fire ring. I am going to pull it off tomorrow to see if it's sealed right there from the dump. No smoke on start up. A little under boost, nothing major. I do need to check the gasket on the turbo as well, but in did check the bolts. Lastly I have no idea if the turbo has an o ring behind it and the front and rear are tight. I took a video trying to get a better sense of the sound and the car definitely sounds weaker than previous times I have filmed it. No real distinctive spool and wastegate sounds like it's starting to open prematurely.

 

It is possible the wastegate is not clamped shut and allowing boost pressure to go by it would be like having a boost leak except at the gate similar to a leaking valve not really noticable until you do a leak down with the cams removed.
This would be my first suspected area.

 

New gate should be here by the end of the week. Hopefully this solves the problem. Thanks for your help man. It's greatly appreciated.