Boost Leak?!

[Sberk06]

ok soo heres the problem..
when boosting and i hit 4500 rpms i lose all of my boost.. it really holds back and wont boost any higher... if i dont boost hard i can easily go above 4500rpms... i did a leak test and found a few around the throttle body, but i fixed that as far as i know..
i replaced the throttle body with another used one and it still does it (what are the odds a different throttle body has the same exact leak)

i sprayed carb cleaner all around the throttle body and intake manifold hoping to find the leak becuase of the engine stalling but found nothing...

what do i do it is verryyy annoyingg......

[koho2731]

What turbo, waste gate setup, proting, psi your trying to run? The last time I saw something simaler to this was on an EVO VIII and the WG was bent.

[Sberk06]

stock t25.. im looking for a 16g or 14b swap asap

[ej20wrx123]

when you did the test did you spray soapy water everywhere? Cause that really helps to pin point the leak

[wgknestrick]

If you aren't pressurizing the entire intake track and soaping it down, why are you wasting time posting here? If you can hold 20 psi for a couple of seconds in your intake track, you are fine. Note, it will always eventually leak out through the valves/pistons unless you can garantee that all intake valves are closed.

Carb cleaner is about the worst way you can check for leaks on a turbo car. It does nothing as almost all "leaks" are sealed at idle.

[JDM87]

your wg probably isnt holding the boost...i had the same problem when i had my gsr and had to go external if i wanted to boost higher.

[TalonTsi97]

you still using the stock bov? how many miles on the car? do another boost test and make sure you check all pipes to. cause i noticed when i do the test you will only hear 1 leak at a time then when you fix it and redo the test you hear a new one.

[Sberk06]

im running..
-stock boost as far as i know
-hks ssqv bov
-just about blown t25 turbo (REALLY NEED A 14B... LET ME KNOW)

when we did the leak test we did it on a air compressed and sprayed soapy water everyyywere.. i tried the carb cleaner a few days ago...

how do i make my own leak tester.. it looked like he used half of a paintballing Co2 tank and a gauge.. but i have no idea..

[Sberk06]

the most annoying thing is, i hear nothing when i just rev the car upto 7000 in my driveway.. but the second im in 2nd gear i can hear the leak.

[Sberk06]

ooh an sorry there are 97,000 miles on the car

[koho2731]

www.VFAQ.com has a how to for a lk tester. Why do you think your turbo is blow(shaft paly, smoking, ext)?

[Sberk06]

no power at all really, even when not going full throttle, supercharger type noise, small amount of smoke sometimes...

[Honduh]

just for future reference free reving to 7k is a good way to stretch rod bolts.

[koho2731]

Originally Posted by Sberk06

no power at all really, even when not going full throttle, supercharger type noise, small amount of smoke sometimes...

Just because the car feels like it has no power doesn't necessarily mean the turbo is blow. You could have something as simple as fouled plugs.

[TrboChicsRock]

It's extremely common for the seals in DSM throttle bodies to leak, which is probably what you're hearing. It's such a minor leak though, that you really wouldn't feel a difference in power or lose much boost pressure. I think your problem is coming from something else.

Are you venting your BOV? Do you have a boost gauge?

[TalonTsi97]

Originally Posted by TrboChicsRock

Are you venting your BOV? Do you have a boost gauge?

They were also my next questions.

[JDM87]

i think its the wg.

[TalonTsi97]

Originally Posted by JDM87

i think its the wg.

its a stock turbo that usually doesnt have any problems, unless someone really played around with something.

[wgknestrick]

First, reving to whatever RPM will do nothing. Turbos work on load. There is no load at idle = no boost.

Free reving does not put any more stress on rod bolts as does reving that high under normal driving conditions.

If you have a leak, the car will feel down on power, period. No boost = no power.

Make SURE you don't have a pre turbo exhaust leak. Those will kill power and "seem" like a boost (cold side) leak. Easiest way I've found is to start car up cold, take a micro swivel mirror and pass it around the flanges. If you see moisture (water from combustion) on the mirror, you have a leak there. Once the car is so hot, this doesn't work.

I always diagnose the hot side things first, then move onto the cold side when troubleshooting.

To make a tester, just buy a pvc plastic plumbing pipe. Drill a hole in the center and install a bicycle valve seal. Conect it to the intake of your turbo and pump away. Watch (attach) your pressure gauge because you don't want to over pressurize it. Wear safety goggles as pipes popping off even with 20psi are violent.

[TalonTsi97]

Originally Posted by wgknestrick

1)First, reving to whatever RPM will do nothing. Turbos work on load. There is no load at idle = no boost.
2)Make SURE you don't have a pre turbo exhaust leak. Those will kill power and "seem" like a boost (cold side) leak. Easiest way I've found is to start car up cold, take a micro swivel mirror and pass it around the flanges. If you see moisture (water from combustion) on the mirror, you have a leak there. Once the car is so hot, this doesn't work.
3)To make a tester, just buy a pvc plastic plumbing pipe. Drill a hole in the center and install a bicycle valve seal. Conect it to the intake of your turbo and pump away. Watch (attach) your pressure gauge because you don't want to over pressurize it. Wear safety goggles as pipes popping off even with 20psi are violent.

1) reason why you rev and boost gauge doesnt go into psi
2) good idea i never thought or heard anyone do that before
3) lol i never saw or had that happen to me when doing one, but would be funny to see (as long as no one gets hurt real bad)