wastegate leaking air

[r1alex]

whilst boost pressure testing my aby avant I knew it had a boost leak but coul'nt find it, i removed the airbox completely, to give me better access to the turbo outlet hose. As the pressure dropped i could hear air , but not from the outlet pipe.
just to see i removed the testing bolt just down stream on the turbo , sure enough, air escaping down the exhaust.
To check if it was the turbo or the wastegate i blocked the pipe to the wastegate, and tested again.This time no pressure loss through the exhaust. although the pressure still drops at amuch slower rate so more boost leaks elseware.I can also only test to 1 bar as that is all my tesco coffee jar lids will take.
So my question is ,is my wastegate knacked it is not leaking above the diaphram, it's loosing pressure into the exhaust.

[terrybullwon]

Alex to test the WG unplug the vacumme hose from the N75 and suck
(dont let your nieghbours see they will think your nuts) This will give you a good idea if the WG is stuck or the diaphram is shot.

Cheers James

[r1alex]

i have removed the wastegate cap, the diaphram is ok and the valve moves up and down freely.

[terrybullwon]

Ok,
Well you will always get a little air pass through the intake valves and the out the exhaust valves if they are in the right places, try blocking off from the throttle body or just even the intake pipe that runs along the cam cover.
You dont reall need much more pressure than 1bar

[r1alex]

the problem is i am loosing pressure into the exhaust surely this can't be right?

[terrybullwon]

well these two possible ways for the air to get there now,
1. through the valves and out the EM
2. Passing through the oil seals on the turbo if this is possible?

[r1alex]

james, all my pressure testing has been done with the crank case hose plugged and the inlet plugged where the steel pipe into the im starts, so all i am testing is the maf hose ,turbo out let to ic ,ic, ic exit hose and of course the wgfv inlet and outlet. there is no pressure to the inlet manifold . i can't see how the waste gate should seal between the diaphram and the valve it'self other than the bush the valve stem runs through.

[r1alex]

anyone got a spare wastegate for sale?

[newsh]

You're losing pressure down the wastegate valve guide, pretty normal as the guide never seals completely, yours does sound quite bad though. With the top off the WG can you wobble the valve stem sideways a lot? if so its knackered, not sure if this can be refurbished. Block it off and keep looking for more leaks. Mine leaks a little at the throttle body pivot too. Check all the tiny hoses and the injector seals. Do the Mark H mod!

[r1alex]

newsh , i did some more forum searching late last night,and found a thread in which i belive you and s2 central were debating this very problem.
The amount of movement and air loss I have makes me think it would be better to replace the wastegate if I can find one .
As for my other air leaks, I have to drink more coffee first, as another coffee jar lid laid down it's life last night in the eternal quest for my missing boost.