Hello guys

I'm in the middle of a boost leaktest and I found a leak just under the Y-pipe. But I couldnt figure out where it came from, so I started to dismount the Y-pipe. But I couldnt get it off, it seems like it's holding in the connection to the plenum valve. (I've loosened the hoseclamps).

Anyone know where the leak can come from and maby tell me whats holding the Y-pipe?


Thanks for all answears

 

I believe that #30 (4-way) connection is below there.
For y-pipe, make sure the 2 secure bolts are removed, the 2 large boost hoses disconnected, the F-hose disconnected, throttle clamps loosened. I had to pull hard and twist mine to dislodge it.

 

There should be a third bolt connecting to the ac hose, on the right side of the Y pipe. To get to the 4 way connection, #30, the TB has to come out. However that's an unlikely source.

There is a hose the connects the the Fpipe, its sort of underneath the ypipe, good luck.

 

maybe plenum is leaking...known problem

 

Thank you for your response. Ill continue the search and I'll give you the answear on where it was leaking when I know it

 

Pressurizing form the turbo outlets and into the engine. I hear this hizzing noise when I go past 15psi - 0,7/0,8 bar.
I can feel some air blowing out from under the Y-pipe. I have spraying with leakfinder but I can not see any bubbles. So now I don't what to do

 

Under the pipe/throttle area there is a 4way vacuum line. I'm guessing that could be one of the potential spots that it might be leaking. If this is the case one the #21 check valves is leaking.

 

I found out that the leak was comming from the bottom of the seal between the plenum and the intake-pipe to the cylinder heads. So now I'm waiting for some good **** to harden over night. Then Tomorrow evening I will pressurize it again and see if I have any more leaks. But this was a big one..

 

there was nothing under the Y pipe as far as vacuum lines that can leak like I told you on Fb... glad you found it...

 

The only thing under there was Nr:30 in Jeanmarcboilard's picture. But the original plenum got a little lip at the bottom of the gasket, it was there it was leaking good things!

 

So was it the black o ring on the the throttle body ? That was my first guess when I told you to look.

 

Yes it was, but it took some time to figure (my first time doing this). Because when i got the Y-pipe off, I had to modify my pressure flange thingy with some garden-hose and glue Then the glue had to harden for 12 hours before I could mount it directly onto the plenum rubber coupling..

 

Right. I made a special tool just for that testing.

 

Same We'll, now I just have to see if the engine has any more leaks. I dont think so, but We'll see tomorrow

 

Some pictures





This is my item modded with garden hose





Here is where I fitted it to get a better pressuretest (more space with Y-pipe away)





My blind hub when I tested from the turbos.