Blown Turbo or Boost leak??

[hottboost]

I just finished with fixing a boost leak and getting my spike under control. Car held fine and I was able to get a good tune yesterday. When I ran it this morning I went wot to see if the tune was right. It help 20psi till redline. The next time I went wot it only spiked to 17psi and held 14 till redline. The turbo is sounded a little different. Like a very loud hissing, never sounded like that befor. It isnt blowing oil out the exhaust. Does it have to blow oil to be going out? When I worked on it yesterday It had very little shaft play! Also could it be possible that another boost leak happened. The turbo has about 4000 miles on it and I have put it through its steps. Just looking for a little input. Thanks in advance for the help.

Carl

 

[Eclipse98_RS]

The hissing sounds like a pre-turbo exhaust leak. I have the same deal on my 98 GS-T right now and it wont build the same amount of boost it used to. Check all your bolts make sure they are there and tight, if they arent theres your problem.

 

[hottboost]

I have had exhaust leaks befor but I wont say that is not it. So your saying maybe the manifold or manifold to turbo?

 

[hottboost]

We did a boost leak test this morning. Vacuum line tore and pcv valve is leaking. Fixed vacuum line and am waiting on a pcv valve from mitsubishi. I have went through 4 aftermarket ones!

 

[Eclipse98_RS]

Let us know if the leaky PCV valve fixes the issue.

 

[donmagicjuan]

Good luck with the new valve. One thing to consider is attaching your leak tester downstream of the turbo. It's a quick way to identify it as an intake system leak or a problem with the turbo.

 

[hottboost]

The vacuum line took care for the leak for the most part. It will hold 20psi now. The pcv valve is letting air through on the boost leak test unless you clamp the hose. Thats why I am replacing it. It is back to holding boost now.

 

[hottboost]

Good luck with the new valve. One thing to consider is attaching your leak tester downstream of the turbo. It's a quick way to identify it as an intake system leak or a problem with the turbo.

Yeah I had knew that ahead of time. I just wanted to try and get an idea ahead of time.