D5 (2005 on) 185 boost problem help please

[5cilinder]

Originally Posted by d5sport

Been messing about today, found a small leak

There is a 90 degree pipe just under the sump which comes off the turbo, one of the jupilee clips has a small screw in it (not sure why?) but it was leaking badly out of there could'nt get the screw to seal so tryed a slightly bigger one and works, no leaks

also made a device to pressure test the intercooler, tested it to 20 psi, had no leaks

now its all back together there is a bit more of a kick through the gears, but there is still a Pssssss noise as the turbo builds up pressure in high gears, is this normal on D5's??

It shouldnt be "normal" in the sense that diesel turbo's dont use dumpvalve's on the chargeair side.
Now you excluded/leaks in the charge-air side maybe there is a small leak in the exhaust system wich creates the sound

[deano2614]

You need to be 100% there is no leaks on the intake side the best way is to use a smoke meter,blown intercoolers and split change and vac pipes are very common.