Turbo boosting problem....

Hey guys,

My turbo setup was running beautifully until I decided to replace a leaky oil drain gasket on my turbo. After I put everything back together I can't seem to keep more than 7psi. And it peaks to 7 and drops to 5. This happens no matter what my boost controller is set to. I even disconnected my reference line to the wastegate and it still does this.

When it spools up it sounds fine and when it hits 7 I can hear some kind of exhaust/air leak noise come out from under the hood. You can a very quick pulsating noise that the leak is not a constant thing. And it closes after boost is gone.

I've reconnected all of my intake piping to make sure it wasn't that. I even removed the section of pipe with my BOV and replaced it with a new pipe to take that out of the equation. I've put my vaccume reference line to the top of my Racegate to help keep it closed and it does the exact same thing.

I know I do have some pre turbo exhaust leaks, but if I can get the turbo to spool up to 7psi the leaks aren't big enough to keep it from spooling past that point.

I'm at a total loss of what to try next to fix this problem. If anybody has any suggestions please let me know, I'm very desperate.

Nobody has any suggestions?? Come on you turbo gurus I know someone must have run into a problem similar to this before. Please Help.

Check to make sure your clamps are nice and tight on the compressor side...

The boost curve prior to the 7psi is the same as before I messed with the turbo. It shoots up there no problem. But once it hits 7psi it makes a lound noise under the hood like something got blown open and the psi stops rising and slowly drops to 5. Then when I try it again the same exact thing happens, like the thing that got blown open resealed and gets blown at the same point. Something with a large enough leak to let out enough air to keep the turbo from spooling any further.

Where can I find my crush gaskets?? All pressure sensing lines have been disconnected. This is happening with no reference on the wastegate. The wastegate was removed to get to the turbo, but if it leaked there I would think it was a constant leak.

Using no wastegate, have you disconnected the pressure side of the compressor from the engine?

I'm not sure what you mean about this. The compressor side was always hooked into the TB through the intercooler and intake piping. The intake piping was hooked to the wastegate, but that has since been disconnected and plugged. The compressor port for reference has always been plugged.

Well, I ordered a bunch of T-bolt clamps for the intake track. I didn't think I would need them with under 10 psi, but I'm out of ideas. I've looked over everything and it all looks just fine. We'll see if the clamps do any good.