Test Pressure

[audiman]

Im really sorry, but i dont understand. I think you meant that the air escaped from the intake hose side and not wastegate side??

[The Spanish]

Im really sorry, but i dont understand. I think you meant that the air escaped from the intake hose side and not wastegate side??

You were quicker than me editing the previous post

@ Tom: During a pressure test with engine off. Is any air suppose to go through the WGFV in the wastegate direction? Or is the WGFV blocking that route?

[audiman]

I think that it should be blocked. I cant remember. I will check.

[The Spanish]

I think that it should be blocked. I cant remember. I will check.

Thanks Tom, please double check that if possible.

@ wastegates: Dice que el camino a la wastegate deberÃa estar bloqueado, pero que lo va a comprobar. ¿Tienes la tuya bien instalada?

[wastegates]

I think that it should be blocked. I cant remember. I will check.

Sorry

[The Spanish]

Sorry

By the scheme it looks like it should not allow any air into the wastegate unless is open by ECU.

[audiman]

No it appears that it will allow air to escape. Try changing it and if it still does it then check the wastegate. Dont think mine leaks.

[The Spanish]

No it appears that it will allow air to escape. Try changing it and if it still does it then check the wastegate. Dont think mine leaks.

@wastegates: Dice que es posible que pase algo de aire que pruebes a cambiarla (aunque si es nueva no va a ser) Donde si que no tiene que salir algo es de la wastegate.

Thanks, He will check both WGFV and Wastegate, then will post test results.

[jameswkr]

The WGFV will allow pressure to pass with the electrics switched off - its failsafe that way and allows you to limit boost if others are working on the car. Try driving with it disconnected and then connected. Disconnected, max boost is mechanical only and should be .4 to .6 bar. Connected should see up to 1.2 bar on overboost and certainly more than if disconnected. If no change then WGFV needs checking/replacing, or wiring is faulty. WG cap should not "leak" with pressure applied to the other side of the diaphragm but it is not air tight if running vacuum checks using the vent nipple.

[S2central.net]

James is right. With WGFV resting (ECU off) it directs boost pressure to the wastegate.

The ECU provides *higher* boost pressure than WG spring alone, because it provides a mechanism for presenting vacuum pressure to the WG control chamber - very rapidly switching between boost and vacuum lines - to present a modulated 'control' pressure to the WG.

The control hose the WG chamber should be blocked up during a leak test, as the control chamber in the WG is NOT air tight. You'd think it would be - but its designed not to be.

However, if air is leaking out of the *upper* WG chamber, then the WG diaphragm must be split.

Paul

[The Spanish]

James is right. With WGFV resting (ECU off) it directs boost pressure to the wastegate.

The ECU provides *higher* boost pressure than WG spring alone, because it provides a mechanism for presenting vacuum pressure to the WG control chamber - very rapidly switching between boost and vacuum lines - to present a modulated 'control' pressure to the WG.

The control hose the WG chamber should be blocked up during a leak test, as the control chamber in the WG is NOT air tight. You'd think it would be - but its designed not to be.

However, if air is leaking out of the *upper* WG chamber, then the WG diaphragm must be split.

Paul

Yes air is licking throuth the upper WG chamber. He says he can blow through the tube and make the wastegate leak from the top.

@ wastegates: Que si sale aire por la parte de arriba de las wastegate el diafragma esta roto, ya que no tiene que salir nada por ahÃ.

[S2central.net]

If the upper chamber has been modified with nut & bolt, then this part of the chamber will not be airtight. That is OK - as the upper chamber hose sees ambient pressure anyway.

Plug up the UPPER chamber hose, so a leak test with the CONTROL hose fitted and see if air leaks through the upper chamber. If it does then the diaphragm is split.

Paul

[The Spanish]

If the upper chamber has been modified with nut & bolt, then this part of the chamber will not be airtight. That is OK - as the upper chamber hose sees ambient pressure anyway.

Plug up the UPPER chamber hose, so a leak test with the CONTROL hose fitted and see if air leaks through the upper chamber. If it does then the diaphragm is split.

Paul

I think it has never been modified I will ask him.

You are saying to block the hole on top of the wastegate and perform the pressure test again?

[S2central.net]

If its a stock WG, then the only place for air to escape from the top chamber (with a diaphragm leak) is this top hose.

yes - plug the hose and test again - air should then only escape to the LOWER chamber thru normal function of WG valve.

Actually a little vacuum pump (mityVac) is the best way to test this in isolation.

Paul

[The Spanish]

@ wastegates:

Puedes poner una foto de la wastegate indicando por donde pierde aire?

Saludos