Engine/Transmission (1998.5 - 2002) Boost or turbo noise above 18psi...

[rotohead]

I've been trying to track down a boost related noise for a month now. It comes on at about 18psi and increases up to max boost (about 32psi). I've replaced hoses, checked for leaks, looked at the turbine wheel and inter housing and intake horn gaskets with no obvious signs of leakage and still have the noise. Any ideas? Do these intake gaskets go bad often? It's very hard to tell where this is coming from when driving and that's really the only way to reproduce the noise is under driving conditions. Any thought's would be very much appreciated.
Chuck

 

[rotohead]

Found it... the plastic air line for my boost gauge had become loose where it fits into the intake manifold. Cheap fix but hard to diagnose.

 

[Vaughn MacKenzie]

Good job. . . I was going to suggest the gasket at the air horn or the one under the intake plate.