Boost leak

[Tesa]

Hello,

I need to help with possible boost leak.
I tell you the behaviour of the car :
1) Idle and vacuum (boost 0bar) - the car behave like always
2) Boost till 0.8bar (1.8bar absolute) the car pushes realy hard, without any issues.
3) At boost after 0.8bar, you can hear really loudly, that the air is comming somewhere out of the system, and the boost is raising very slowly (to 1.2bar), but the car is not accelerating as it should.
4) When I release the throttle pedal, to get under 0.8bar boost, the car behaves normaly as before, and you also cannot hear any sound of boost leakage.

I checked all the boost hoses (put them out, wash them and visualy checked) and I replace all the hose clips. I didnt see any damage.

Also the DV valve is looking fine, when I tried to apply vacuum to the small hose on it, it moves, and holds pressure.

The should boost to 1.5bar as it did before this issue.

Do you have any thoughts - what should I check ?

Thanks,

Radek

[Rusty]

As ever, you need to use a bung to pressurise the whole system to over 1 bar gauge and check for leaks that way. Visual inspection isn't really worth the effort, as I've found many, many times.

Is the car standard?

[UrS4boy]

...Do you have any thoughts -..?
Thanks, Radek

Yes, like Rusty says boost leak testing. Here is some info that you should find useful:

http://www.s2forum.com/forum/showthread.php?t=63974&highlight=boost+leak+testing

[Tesa]

Thanks guys, I found a leak here (image from link you have sent me) :


and also its slightly leaking between the throttle body and intake plenum. It seems the gasket is worn..

Radek