Leak Test

[no-boost]

Hey guys i have a 90tsi awd talon ,new to the 4cyl. games formly v-8 guy my ? is i did a leak test on my talon and found no leaks at all except air coming out the corner of the valve cover, not sure would this be a bent valve? car runs great except it only makes 6psi of boost , it pulls 15 to 18 psi of vac at idle . no mod except open air box and k-n filter and an after market boost gauge
any help woud be great on how to get more boost
thanx james

 

[I-luv-em-all]

check the turbo for shaft play, it may be time for a new turbo.

 

[no-boost]

there is no shaft play ,would a faulty blow off valve cause it not to make 6psi of boost when i did the leak test the bov did go off i had 20 to25 psi in it according to the gauge
any one
james

 

[Spln_Hrd]

i would guess its the turbo too. i don't think they have to have shaft play to be bad

 

[91 white tsi]

well i need to do one my self but im not to sure exactly how to do the leak down test i think you some how fill it up using a aircompressor and adapter with valve but not sure please help

 

[psychlow]

91 white tsi - http://www.vfaq.com/mods/ICtester.html

If you have air escaping from the valve cover, you need to replace your PCV valve or route it so that it dumps to the ground with a catchcan and plug the intake. See the below link.

http://www.tgilmore.com/talon/catchcan.html

James, how does your turbo look? Is the wastegate actuator hooked up correctly? Are there any pre-turbo exhaust leaks, like cracks in the exhaust manifold or no sealing between the mani and the turbo? Is the car fast, other than the low boost?

If the car is retarding timing enough because of your ECU picking up knock from the knock sensor, that can cause low boost.

 

[no-boost]

yes the car feels fast but acording to my buddy its not as fast his stock talon he pulling 10 to 13 psi there was a crack in the mani but was welded not leaking there though small leak out the bottom corner of the ex mani

 

[91Bomb]

According to the chilton mamnual when the knock sensor detects knock (real or not) it signals your wastegate solenoid valve to limit boost to between 5-7 lbs. This has happened to me.
Check that the vacuum lines to the wastegate solenod valve and to the wastegate actuator are in proper sequence and in good condition. Chk trouble codes to see what you get. Chk wastegate solenoid for function and chk knock sensor.

Stock boost is approx. 10-10.5 lbs. If your turbo was shot you probably wouldn't see a consistant and steady 6 lbs and you'd probably be seeing some smoke and/or notice boost fluctuation.

 

[whitegst97]

I had a general question about leaking, and leak tests with the bov's. I searched and ended up in this thread. Is the bov suppose to leak, from the actual return tube when performing a leak test, my greddy type S leaks at 10 psi or so, and two other 2G stocks also leak like at 5. I pressurize the system and i leave the nipple connected on the 2G stock and the top nipple on the greddy. At around 5 psi they start to leak. Is this suppose to happen? Thanks