Installed MBC, now BOV is making Screeching noise?

[tranceman]

This past weekend I finally got around to installing my boost gauge and Joe P MBC. The install went fine, no unusual problems at all. Got everything working great, as well as dialing my boost in at 15 lbs. Yesterday I started to hear wierd noises coming from the BOV area. When the turbo spools all I hear is the normal turbo spool, but as soon I get to 10lbs or so I begin to hear a progressively louder whining/shrieking sound until I blow off. Blow off sounds normal except for the fact that it seems a lot louder and harsher then before. Upon searching I found some threads mentioning a rubber sheet inside of my HKS SSQ BOV that may be going bad, as well as the whole BOV itself going bad. I haven't done a boost leak test yet, but intuition is telling me thats what it is. I do know for sure that the MBC is installed correctly and that all the vacuum lines were hooked back up correctly. My question I guess is, do you think this sounds like a boost leak, or is my BOV going bad? There are other threads mentioning this same thing, but no answers in them. Mods are listed in my profile.

 

[ddavisaf]

Check your turbo for shaft play just in case. Piece of mind.
Then boost leak test at 20 psi... that will tell all.

 

[Talesin]

Keep in mind that you're running your turbo harder than you normally did. Obviously it's going to have a different sound after you exceed the prior maximum. Mine picked up from a quiet whistle to a loud almost jet-engine tone when I set it to 16psi. No shaft play, no leaks, stock CBV.