boost leak problem

[mikehz]

Hi all,

For about a year now, I've had this persisting noise when I come on boost, which sounds like a very obnoxious boost leak. Got a video of it here, before any mods
http://www.youtube.com/watch?v=vXp0ydOPVJk

Initially my mechanic said it was the turbo, so I got a vf52. The noise remained and Matt tuned it and said it is most likely the throttle body hose being blown, similar to another one posted here not long ago.. So I got a silicon hose & got a turbosmart plumb back bov. Noise is still there

We noticed that the bov isn't really making any noise, compared to my cousins stock bov (similar mods, vf52, he has no dump and a k&n panel filter).
we suspected it could be the intercooler so we put on another stock one, issue was still there...

im not sure what else that leaves, besides intake manifold and the up pipe. howver given the turbo was recently installed by a reputable workshop, they should have noticed something during the install if it was these two.
weve checked all obvious vac lines and there was nothing out of the ordinary.

at a loss at what it can be... keen to hear what you guys think it could be
my mods are vf52, silicon tb hose, ultrex full tbe exhaust, 3port solenoid, turbosmart bov, resornator delete

cheers,

Michael

[Newbie GT]

Hi all,

For about a year now, I've had this persisting noise when I come on boost, which sounds like a very obnoxious boost leak. Got a video of it here, before any mods
http://www.youtube.com/watch?v=vXp0ydOPVJk

Initially my mechanic said it was the turbo, so I got a vf52. The noise remained and Matt tuned it and said it is most likely the throttle body hose being blown, similar to another one posted here not long ago.. So I got a silicon hose & got a turbosmart plumb back bov. Noise is still there

We noticed that the bov isn't really making any noise, compared to my cousins stock bov (similar mods, vf52, he has no dump and a k&n panel filter).
we suspected it could be the intercooler so we put on another stock one, issue was still there...

im not sure what else that leaves, besides intake manifold and the up pipe. howver given the turbo was recently installed by a reputable workshop, they should have noticed something during the install if it was these two.
weve checked all obvious vac lines and there was nothing out of the ordinary.

at a loss at what it can be... keen to hear what you guys think it could be
my mods are vf52, silicon tb hose, ultrex full tbe exhaust, 3port solenoid, turbosmart bov, resornator delete

cheers,

Michael

Air box leak ??

[jslayz]

hose to BOV at manifold end has just popped off?

J

[bigBADbenny]

Why not do a soapy water test, carb cleaner in engine bay whilst logging test, or smoke test?
I've linked how to in the pretune FAQ, and they're all googlable.
If you are local I can help diagnose

[mikehz]

Thanks guys,

Dont' think it would be an airbox leak, but I will check that out.

Don't think the BOV hose at manifold has popped off, we checked to make sure they were in

Will give soapy water test a go, will pretty much need to spray everything haha.

[bigBADbenny]

Yeah do the zorst too on a cold startup.
The bubbles will be obvious on it and in the engine bay.

Have your passenger listen to the gear stick using a stethoscope or screwdriver handle to ear, tip on the gearstick shaft.
My hunch this minute is it's the gearbox

I'm keen to make a smoke tester, the Baur has an inlet leak for sure...

[Newbie GT]

Yeah do the zorst too on a cold startup.
The bubbles will be obvious on it and in the engine bay.

Have your passenger listen to the gear stick using a stethoscope or screwdriver handle to ear, tip on the gearstick shaft.
My hunch this minute is it's the gearbox

I'm keen to make a smoke tester, the Baur has an inlet leak for sure...

Good point benny possible gear box

[<GB>]

Does it only do on boost at any gear ?

[mikehz]

Yes, only on boost and in any gear

It is worst when the cars only been running for <5-10minutes, afterwards it is not quite as bad, but it is still there and easily noticeable

[jaydece]

just putting it out there?

maybe around the TGV area....or its surrounding components...so not just the TGV themselves....but everything that connects and manages it...you would need to remove the TMIC to get a good birds eye view....especially around the back of the engine...

But it does sound like a vacuum leak of some sort.....

Yes check leaks by suggestions above....I do it by using a compressor and pressuring the intake system and hearing the compressed air escape. But I have a blanking plate and a air line feed for my intake pipe....but its specific to me....above suggestions work just as well...

You'll be suprized to find how many hoses in our engine bay are not clipped, cable tied or clamped......poor effort from subaru...

[<GB>]

To me that noise sounds like a flange exhaust leak they always sound better once warmer cause the metal expands in the exhaust

[norbs]

To me that noise sounds like a flange exhaust leak they always sound better once warmer cause the metal expands in the exhaust

This! Check the flange on the turbo hotside to intercooler. I bet it is either not tight or the gasket is buggered. Oh and don't assume that because it was done at a reputable shop that it was done right

[kiahatsiu]

To me that noise sounds like a flange exhaust leak they always sound better once warmer cause the metal expands in the exhaust

This! Check the flange on the turbo hotside to intercooler. I bet it is either not tight or the gasket is buggered. Oh and don't assume that because it was done at a reputable shop that it was done right

One should hope the turbo hotside goes into the exhaust.
An exhaust leak of any sort will sound like balls all the time, unless of course it is around the waste gate, and you have a divorced wastage setup. Check the flange Norbs suggested from the compressor outlet into the intercooler.

[norbs]

To me that noise sounds like a flange exhaust leak they always sound better once warmer cause the metal expands in the exhaust

This! Check the flange on the turbo hotside to intercooler. I bet it is either not tight or the gasket is buggered. Oh and don't assume that because it was done at a reputable shop that it was done right

One should hope the turbo hotside goes into the exhaust.
An exhaust leak of any sort will sound like balls all the time, unless of course it is around the waste gate, and you have a divorced wastage setup. Check the flange Norbs suggested from the compressor outlet into the intercooler.

Ahem, yes I meant the turbo outlet. Hot being the compressed air

[bigBADbenny]

You meant the compressor outlet.