Ok well i have a few dumb questions to ask here, i cant post anywhere else yet because i just registered not too long ago on this site.

Question 1- My car makes a rattling noise on deceleration in gears 3-5. The second you touch the throttle it goes away. Seems to be coming from the transfer case area. Its not a heat shiel or anything. So i jacked it up and looked underneath to see if it was something obvious. I was looking at the transfer case from the front of the car and towards the top there in a threaded hole. No plug or anything in it. Is this the fill? Is there supposed to be a bolt that goes in there or just an empty threaded hole?

Question2- My car has a blitz BOV. On almost every other BOV i have heard it makes a single "woosh" of air between shifts or when you let off the throttle. My car makes a fluttering or chattering noise. Sounds like "turbo flutter" or compressor surge or whatever. Im not sure if it has the wrong spring inside or what? The vacuum line coming off of it is tee'd into my manual boost controller line. Is this right?

thanks