Boost Leak Testing (Twin Apexi Pods) - New To Gtr's

[djrobertshaw]

Hi Guys,
I know this has been repeated in alot of places but I just want some hand holding before I connect a compressor to my engine

I have the old hesitation issue where as the car is coming onto boost (boost gauge reads 0) the car hesitates, get over that hump and all is good. I have read that vacuum leaks can cause this so wanted to check for leaks.

I have done the soapy water test with nothing so I was going to follow http://www.gtr.co.uk/forum/174597-gtr-boost-leak-tester-diy.html and http://www.skylinesaustralia.com/forums/topic/250275-boost-leak/?p=4337070#entry4337070 but am not clear on which hose to pressurise.

My plan was to take of the Apexi air filters and sensors, block these both off with PVC piping and caps. Once the intake to both turbos is sealed I would remove the bottom hose (the hose on the right of the pic) off the PCM (photo attached) and slowly pressurise the system.

I cant figure out why to remove all the hoses as the link on GTRUK did.

My other option was to block one intake (say to the front turbo) and pressurise the other with a boost leaker tester? This may be easier

Please let me know if this is daft, sorry if the answer is here but I have searched the forum and couldnt see a clear answer as to which pipe to pressurise.

Alternatively if you are in the Newcastle area i would be happy to part with a case of beer

Thanks,

Dean

Edited March 22, 2013 by djrobertshaw

[hardsteppa]

i would have thought block off one turbo and pressurize via the other one, but never done twin turbos before, only single..

[djrobertshaw]

Hmmm did this test and think I have found some leaks but the dipstick popped out

Is this normal or have I pressurised the wrong but?

Edit: reading a bit about valves could be very bad

Edited March 24, 2013 by djrobertshaw

[Guilt-Toy]

you had alot of pressure in there for the dipstick to come out, before the dipstick came out did you hear any hissing or any leaking coming from anywhere? put water all on the hoses / clamps and see if you see any bubbles.

[djrobertshaw]

I had the regulator on the compressor set to about 7psi (but it never even got there before the noise from the dipstick)

There where some leaks down near the intercooler which I am checking out but just concerned that maybe there is a bigger problem.

I took the hose of the PCM that faces the engine, that is where I pressurised the system.

[hardsteppa]

do gtr's have pcv's? on gtst's the pcv should stop the crankcase getting pressurised by boost when doing this test. Pressurising crankcase will cause dipstick to pop out. First time i was doing this test, was getting leaking from loose/faulty pcv, no further leaking from there after i replaced with new one.

this is with sort that i used

http://www.ebay.com.au/itm/2-UNIVERSAL-TURBO-BOOST-LEAK-TESTER-Tests-any-turbo-with-a-2-comp-inlet-/140922559674?pt=Motors_Automotive_Tools&hash=item20cfa39cba

goes over front of compressor house.

not that expensive, gauge makes it easy to see if leaking from somewhere, just plug in a compressor to the nipple and fire her up.

[djrobertshaw]

hmmm I have been reading about the PCV.

Is there a way to test if this is faulty? I couldn't hear any leak from it...............(well where I think it is)

[hardsteppa]

yeah just a one-way valve going into crankcase somewhere, don't know where it is on gtr's sorry. Should hold boost one way, and not the other. Mine rattled when take off and shaken, and wouldn't seal against pressure properly.

[djrobertshaw]

Thanks for your help hardsteppa, I have found some leaks.

Seems to be all around the IC piping so have taken the blinkers off to reach in and tighten things up, trying to avoid taking off the front bar

Its booked into a workshop with a dyno to check out the problem in more detail.

For the record pressuring from the pipe as above does seem to work but made a second tester with a valve stems and did it the good ol fashion way anyways.