Losing Boost Very Rapidly

[parsapolis]

'02 140k

I'm having boost issues and hoping someone can give me some advice. The wagon only wants to boost to the 8-9psi target if I'm accelerating from 1st gear but I only get 1-3psi on the higher gears. However, most of the time I get no boost on the higher gears. When i do get boost it holds for about one second and it drops to between 0.1psi and 0.1in Hg and it stays there on hard acceleration. This is my first turbo so forgive my ignorance but is it also normal to lose boost immediately on upshift?

I have replaced the TCV and charge pipe hoses but haven't done the CBV since it seems to be a royal PIA and wanted to leave that as the last resort.

One thing I noticed this morning is a clicking sound when the car was cold and the vacuum at idle was sitting at 16in Hg (it normally sits in between 26 and 22in Hg). About 1.5 minutes later the clicking went away completely and vacuum immediately went up to the normal range stated above.

Could I have a leak at the intercooler? Turbo bearings going bad (clicking sound)?

Thanks,
Sia

[parsapolis]

Traced the weird sound to the new TCV (IPD HD TCV). It was also vibrating quite a bit while making the sound. I understand the TCV gets no voltage until boost is required so I'm guessing the internals of the valve are bad since it only makes the sound on idle and while the car is cold. Switched to my old TCV and the sound went away and vacuum is back to normal.

Besides the three vacuum lines to the TCV (wastegate to TCV, TCV to intake pipe and TCV pressure line from turbo) and the one from the intake manifold to the turbo for the CBV are there any other lines I can check for leaks?