My turbo xs mbc makes an air leaking noise at idle. If I pinch the hose feeding the boost controller from the intake manifold I can hear the hissing stop, and the WG makes a noise like it is closing....

Is this normal?

 

Bump, I know alot of people have turbo XS MBCs....

 

Yes this is normal. My friends does the samething and his holds boost fine.

 

thats how it works, it bleeds off pressure so your wg will see less boost.

 

Mine holds boost fine. I just don't see why the boost controller should leak until boost hits the set level.

 

it bleeds air off so the wastegate doesn't see boost presure, when it hit the set pressure, it stops leaking and forces the air to the wastegate to open it.... That is how they work..