I just noticed that my fd3s air bypass valve is not making any sounds (psst) like it used to when I let off the gas. Any ideas whats going on with this factory unit?

 

What's your boost pattern?

 

My boost pattern is normal and so is the vacuum. only the sound from the bypass valve that is absent.

 

Do you have the stock BOV with the stock airbox? If so, try disconnecting the hose to the airbox and see if you can here the BOV to verify it's venting. I'm sure it is as you'd hear a different sound if you had compressor surge.

 

I have the HKS intake system and the BOV vents outside the intake. It was great (OEM air bypass valve) last summer and now this year after the winter storage I have not heard any audible sounds like before. The sound was very noticable before. This weekend I will fool around with it.