did a boost leak test

[91dsmeclipse]

i did a boost leak test on my 92 gst becuz when i dont have my lights on it idles and 16 vac(after market boost guage) and when i put the lights on at night the vac is 10-14 and it the needle shakes but when i did a boost leak test i heard all the air coming out of the turbo from somewhere i couldt pin point it i know for a fact its comiing from the turbo should i just buy a new turbo or can i fix it ( i know im going to have to replace it eventually anyway if anyone has a big 16g let me know used or new)

 

[oldman]

I think soapy water might be cheaper than a new turbo.

 

[1fast97gsx]

IF you can't exactly pinpoint it then add way more air and a lot faster so the hissing will get REALLY loud. Keep doing this until you pinpoint it. Screw big 16gs ... get a real turbo.

 

[theSicKness]

IF you can't exactly pinpoint it then add way more air and a lot faster so the hissing will get REALLY loud. Keep doing this until you pinpoint it. Screw big 16gs ... get a real turbo.

yea.......except anything over 20 psi w/ a boost leak tester could blow ur head gasket....id just go w/ the soapy water thing it is alot easyer to c a bubble


Jesse

 

[91dsmeclipse]

what u mean get a real turbo and what turbo in your mind is a real one? i dont want to race people waiting for my turbo to spool up.

 

[oldman]

You have not even find the leak at the turbo yet, why are you assuming the turbo is bad? It can be as easy as the J-pipe gasket. What problems led you to the pressure test?

 

[Black95TSIawd]

testing over 20 psi might make your headgasket go?

 

[Stapl3]

2g head studs are assumed to be only good until ~22psi. Few have done 25. It's a tuning thing, I wouldn't really worry about it when it comes to leak testing.

I personally would boost leak test to 25psi. Use soapy water in a spray bottle to find where the leak is around the turbo.

Best of luck.

 

[1fast97gsx]

yea.......except anything over 20 psi w/ a boost leak tester could blow ur head gasket....id just go w/ the soapy water thing it is alot easyer to c a bubble


Jesse

Are you kidding me? Do you have any idea what a boost leak test does? Do you know the difference between psi, airflow, detonation, and what causes a headgasket to blow????

 

[Staytuned]

Yes static pressure like 20 psi isn't going to do squat to a HG. It's detenation, high boost plus normal combustion chamber pressure from .....well combustion that will make it go.

 

[1fast97gsx]

Considering generally the valves are for the most part closed anyways during a boost leak test so the air can't even get to where the headgasket is. If the "boost" is so bad that it will blow headgaskets doing this simple test ( assuming valves are open and the air gets into the combustion chambers ) why do you suppose throttle body gaskets and such don't blow during the test then?

 

[deusxmachina]

when i did a boost leak test i heard all the air coming out of the turbo from somewhere i couldt pin point it i know for a fact its comiing from the turbo should i just buy a new turbo or can i fix it

A boost leak means a gasket or coupler is bad or loose somewhere. If it is coming from the turbo, it could just be the gasket for the compressor cover. Usually replacing a $10 gasket is cheaper than buying a new turbo.

 

[oldman]

Open the oil cap during your next pressure test and take a listen, you can also be passing air though the turbo seal as well which is sometimes normal during a static pressure test as long as it's not leaking oil during operation.