today i checked for boost leaks with the cap on the inlet of the turbo ... I pressurized it to about 15psi and it drops pretty fast...Im pretty sure somewhere on the throttle body is leaking cuz i can hear it ..... Has anyone done this test ????? An how long does the boost hold for????
Any insight????

Regards Paul

 

pressurize it ... then put your finger over the hole .... it should hold for a few seconds ....

 

how are you pressurizing the system? bike pump, air tank, etc?

if you use a bike pump and you have a boost leak, its pretty tough to get much pressure in the system. the bike pump doesnt fill faster than the system leaks.

if you are using an air tank (recommended) spray soapy water over all piping connected to the intake (j-pipe to intercooler, intercooler to throttle body, blow-off valve) and especially the areas you think have boost leaks. the air rushing out should cause bubbles over the leaks. then, just repair. if its a coupler, replace it. if its a gasket, replace it and put silicone around it too. if its a hole in a weld or piping, coat over it with JB Weld and let it set for a few hours.

I had a boost leak in the weld on my j-pipe, just inches from the turbo. I used JB Weld on it, and it held up perfectly. still holds up fine with no leaks, even under high heat and/or pressure.

good luck, and keep us updated.

 

Gst racer im using an air tank and the pressure will hold 15-20psi for about 20 seconds then drop to zero ... I know the throttle body is sapossed to leak a little air through the head ,valve exc.. but i can hear a hissing noise cooming from there an i cant find it .......Everything else is pretty leak free i took a bunch of stuff off an pressurized them by thereselfs.... I have heard of alot of different things like it should hold boost and leak very slow like as in 5 mins???? is that wrong?? Thanks guys i aprreciate it

Regards Paul

 

nah, mine doesnt hold for very long either, and i dont have any bad leaks

 

yeah the air will leak through the throttle plate and into the intake mani and whatever.. the absolutely correct way to boost leak test is to block off the throttle body.

but try the soapy water thing i mentioned. just to be sure. also, I have never seen a stock throttle body gasket that didnt leak. i have a new gasket on mine and then i put rtv on both sides of it, and put everything back together.

 

Well lol do you hear any loud hissing noise ?or is this leak normal

 

Gst racer , if i block off the throttle body and right after the bov put a cap, should the boost stay the same now an not drop ????

 

mine leaks out of where the throttle is, its not the throttle body, but its the throttle itsself, where the cable attaches to. and it is a loud hissing noise.

 

get soem soapy water. and spray it down.where ever it bubbles is your leak.