large hissin noise from under inlet manifold checked and replaced all little vac pipes when you pull on the one that goes under neath the manifold out of the t piece in the centre it quitens down what does this connect too any body else had this problem
the car is a n reg scort cossie with big turbo conversion

 

inlet throttle body plenum gaskets thats the favourite 1s m8

 

thats what i thought but when u squeeze that hose to stop the air gettin through the noise goes ?