Turbo Leaking during boost leak test?

[Prodigyman]

Since I was 90% positive that I have a boost leak (like a huge one) backing up by 200 miles per tank on my 97 GSX and TONS of HP loss, I made a boost leak tester from home depot parts and I have a Hutsky 120 PSI compressor around. I pump it to around 60-80 PSI and connect to my tester. At first I hear A LOT of air escaping from around the turbo (FPBT28 with less then 5000 miles on it) and also from my throttle body switch. I have 2.5" FMIC custom piping + 32" FMIC (check my profile for MOD list) there is no leaks there.

On compressor it goes from 60 to 20 PSI (and stays) in like less then a minute and my boost gage never shows more then 6 PSI period. And throttle body leak is somewhere underneath it where I cant put my fingers so I think it's the gasket which is leaking that I hear is very common on 2Gs.

My question is turbo suppose to leak so much air? I took out my intake and connected the tester directly to the turbo and made sure that its connected tight and no air is escaping. I mean the air is coming out of compressor (cold air) part where it connects to oil intake/exhaust middle part, the round (silver) part. And a lot of air is escaping from it. So is that normal or my turbo is leaking air? If so how do I fix that exactly and I am sacred to ask... do I need to replace/rebuild it? \

Also i took my intake pipe out and there are A LOT OF oil it in (like a little puddle), i took my intake out 100s of time and never saw that before... not sure what is up with that but prob my CEL which just came on has something to do with it.

Any suggestions will be greatly appreciated.

 

[Jeremoose]

*tired, moronic post, pretend this isn't here *

 

[staticbrainwash]

Um. . . no. You unhook the intake pipe from the turbo and place the leak tester on the INLET of the TURBO. Then pressurize the system to 15-20 psi. OR you can test by bypassing the turbo and place the tester on the lower inlet pipe of the intercooler. OR you can bypass ALL of that and test the throttle body directly by placing the tester on the TB elbow.

PS, It sound to me like the turbo is SHOT if you have air escaping from where the compressor vbands to the turbine housing. And the oil in the intake pipe make it sound like the turbo seals are WAY gone.

 

[MrBoxx]

In some cases, the seal between the compressor housing and the CHRA seat where the snap ring holds the compressor housing on can leak. There is a rubber O-ring to seal the compressor housing. If it has deteriorated, it's possible that air can leak past.

If you can get at the snap ring safely, you can take it off, take the compressor housing off, and inspect for damage. Just remember to be careful when loosening the snap ring and be sure to put it back on the right way. There is a slight beveled edge on one side; that faces the compressor housing.

 

[Prodigyman]

Yeah from your description the O-RING is leaking, even thought most mods I installed myself but I really don’t feel comfortable disassembling the turbo thought. And the oil lines to the turbo are brand new I got from SBR with new gaskets and seals and I checked everything twice before I stalled it last year so I don’t think oil is leaking from the turbo.

 

[snox135]

He was suggesting that the turbo is leakng oil internally.

 

[MrBoxx]

When doing a boost leak test, you don't want to put too much air pressure into the system: 20-25 psi is plenty. Too much and you can blow out the seals on the turbo shaft. A couple people on here have done that, I believe. The next time you do a boost leak test, use only about 20-25 psi and spray soapy water liberally all over where you think any place a leak could be. This includes the turbo, intercooler pipes, intercooler, throttle body, and even the fuel injectors and intake manifold. You'll see bubbles where there's a leak. Also, have a friend listen at the muffler for hissing.

Did you check the turbo for shaft play to rule out the bearings/seals failing? Try to wiggle the compressor wheel up and down, side to side, and in and out. Noticeable play in any of these directions is a sign that the turbo is shot. Also, check your lower intercooler pipe for oil pooling in that.