Turbo vibration, light grinding sound when release throttle Waste gate? Any ideas?

[Festival500]

Got back from japfest this weekend and noticed a vibration noise from turbo.

Checked for play on the turbo shaft and had a bore scope in to look for any grinding on housing or damaged blades but absolutely fine.
When I hold/ put pressure on the actuator at turbo end the noise stops. A friend who's a mechanic said it the waste gate seen as we managed to use the scope to confirm that the noise was still there when blades were not spinning. You can also hear the noise when on idle


He used a vac tool and when wastegate is closed the noise stops so we reckon when it's open it just vibrating slightly.

The noise seems to be getting worse though, so any ideas help would be much appreciated.

Cheers

 

[dark_knight]

could*it*be*the*connection/joint*between*the*w/gate*and*the*arm*that*connects*to*the*actuator..?*you*seem*to*have*narrowed*it*down*pretty*much*to*that*from*your*description.*are*you*loosing*boost..?*is*the*nosie*audible*from*the*drivers'*seat..?*is*the*actuator*putting*the*required*pressure*on*the*w/gate..?*does*it*feel*loose*in*any*way..?

 

[weeJohn]

Sounds like the acuator is not holding the wastegate button closed on the exhaust housing and rattling against it just. Can you move the wastegate arm back (into the actuator housing) by hand and does it return to the original position after you do so? It could be the actautor is shot or its moved towards the arm and needs moved back slightly.

 

[Festival500]

Cheers for your replies, the actuator rod doesn't move at all and it's not the pin rattling I'm certain it inside. I have a boost leak from intercooler hose which I got this w/e too so couldn't say if I'm loosing boost as no I am already due to leak. Can hear sound from driver seat and the vac tool showed waste gate closing at 0.65bar but boost gauge shows 0.85. Had a word with turbo dynamics and they said it could be 'poppet' valve or something? Just hope I don't need to replace the turbo.