How to test for boost leak?

I assume if I’m down 6 psi and it was a leak it would be loud enough to hear? Or my waste gate is not fully closed when it should be? It has a issue where the part that mounts in the turbine housing was binding and at one point my wastegate got stuck closed.

 

I don’t want to adjust the length if I don’t have to but what is 1 psi like 10 hp?

 

Normally it should be 18 psi after I had my tune

http://turboboostleaktesters.com/how-to-boostleak-test-a-subaru/

I swear I read a good boost leak test procedure on this site that is for the LGT specifically. I have a 2005. Does anyone know how to find, or can anyone tell me which vacuum lines need to be plugged if testing for a boost leak from the air intake (hose to MAF)?

The lines that go to pcv and crankcase. Ideally you would boost check from the turbo, but Subaru's design keeps that from being feasible..

Not so much a procedure for how-to do but pics of the most common trouble spots thanks to Cryotune Dave

 

https://legacygt.com/forums/showthread.php/intake-vacuum-leaks-and-you-pics-inside-235626.html

I swear I read a good boost leak test procedure on this site that is for the LGT specifically. I have a 2005. Does anyone know how to find, or can anyone tell me which vacuum lines need to be plugged if testing for a boost leak from the air intake (hose to MAF)?

 

 

I use a pint size paint can to plug the hose off the air filter box. Then pull the small hose off the blow off valve. Give that hose a short blast of air from a compressor, put your thumb over the hose, listen for leaks.

If your wategate gets stuck closed you will have too much boost. Low boost is probably an indication that your turbo is stuffed. Unless your wastegate is stuck open, Your turbo may have done its dash.

I found this leak like 2 months ago lol.. the bend going into the throttle body was the issue..

 

 

I really need to get new silicone hoses I just don't know the FMIC pipe size or the TB to FMIC pipe size..

 

 

trust me it's very annoying when it pops off.. happened to me in NYC making a turn onto 11th ave

I plugged the air intake and blew into one of the BOV hoses. Very quickly pressure built and I could put my finger over it for 30 seconds and no air escaped. Air came rusing out when I removed finger.

 

 

I did same thing with the oil filler cap removed and could build no pressure at all.

 

 

Also, connected a home made boost leak tester to the intake and didn't build any pressure except in the oil as when I removed the oil filler cap it was obviously under pressure but didn't seem to be any in the rest of the intake. I was just using a bicycle pump to build the pressure.