Squeal sound

[mdfabia1969]

Disconnected vacum pipe from turbo does not make a squealing noise now under acceleration?getting confussed any help appreciated.i pulled pipe of at vac box on top of strut why is this?

[sepulchrave]

The turbo is obviously making the noise when the VNT opens, this may indicate that the turbo is failing.

[mdfabia1969]

Is it possible its the vac box on top of the strut?

[sepulchrave]

The N75 is simply a solenoid that controls the vacuum to the turbo actuator by bleeding air into the line, the vacuum is generated by the tandem pump, try unplugging the solenoid electrically rather than by disconnecting the vacuum pipe.

[mdfabia1969]

Hi i tried with it with the connector off.no boosting of turbo just same as with pipe off 

[sepulchrave]

Have you checked for boost leaks?