i got this prob since i made conversion to my car...the engine make a loud of noise (sssiiiiiiiiiinnnnnnnggggggg)...sounds like that...damn it...i search around but not find from where it come from...then i thought my turbo was cracked in the ext chamber - always happen to standard n14 turbo...so...i changed my turbo = hybrid with u12 standard turbo...means my shaft and the exhaust side was replaced, but....that it still singing...the sound came out while the boost up begin...syncronisely to the boost...(according to my boost meter, it came out while it start to compress@ starting 0.1)...hope u all can help me down here...

* all vacuum hose checked already=ok...

i think i may have the same sound comming out of my t25. does it sound like a whaling or a whistling noise? mine hits it in vacuum also

yeah...the same sound like ***...may hit to deaf!it sounds like a ball bearing turbos, but it sounds like an aeroplane also...(said my few nismo members round here)...

did you replace the manifold gasket. i know that a mate of mines GTIR had this noise. we replaced turbo manifold gasket and the dump pipe gasket and it was all good.

do u mean extractor (manifold) gasket?the one between cylinder block n extractor?...if that one...i did...but there's still whistling...hmmm...

i think when you hear that high pitched whislting it's ethier a turbo going out. or mine did it when the gasket between the turbo and manifold was leaking.

ok.tq bro...i will follow up soon..

manifold to turbo gasket is bad
i had hte same problem and now it's quiet

i find it hard to believe that it's the gastket.. *** not too long ago i had to pull the turbo out and made sure ALL the bolts were lock washered and tightened. guess next time the turbo comes off... i'll have to check for this >.<

yeah...me too...everythings that wear n tear was replaced after i pulled out the turbo...need to pull it again so..

hold on.. correct me if im wrong.. if there is any air leaking out where gaskets should be.. it would create a ticking noise.. or an exhaust leak. my turbo to manifold gasket blew out once and it made a ticking noise.. not this noise that it's making now.. just thought i'd point that out before you go pulling out the turbo

ok...right after u...