Hi everybody, this is my first post here, been searching and reading stuff for a while, but I have too many questions in my mind so thought will be good idea to post it here. I just bought my first turbo car last week, Its 02 BA XR6T but with fair few K's its got 260 thou K's but girl I bought it from her brother was mechanic and he said he recently replaced turbo and valve springs on it, its also got nice exhaust sound too. I was reading a post somewhere about cleaning boost control solenoid with wd40 and when I went to do it, hose which goes from waste gate to solenoid was disconnected and its very loose so after spraying wd40 I used cable tie to hold it, At what RPM I should be expecting boost to come ? max psi I could push is 5 but I noticed boost is not coming easily, also when it hits 5psi it doesn't hold that boost and I have to put my foot down even further and then it rebuilds again, so where should I start looking for problems ? I tightened all manifold bolts when I had my heatshield off, but didn't had right tool for turbo bolts so couldn't check that. Also I noticed my vacuum on idle sits at around -15 to -16 and doesn't go any lower then that, my mates wrx sits at around -20 so is that alright ? It also idles rough at lights when warm, runs fine when cold, also if I move my shifter to N it idles fine, My fuel consumption is also very high its showing 20.1 L 100/KM and I have only hit boost few times. My rwc also says "rear diff mount cracked" and I also noticed lots of oil around diff, how much should I be expecting to pay for that ? I got my car booked on Wednesday for service, So they'll be changing oil, filter, wheel balancing, coils, plugs, and possibly fuel filter too. Rough idle is not a big issue atm, only thing I am really worried about right now is diff, because its leaking oil so would it be safe to drive ? I also hear clunk noises when going over small bumps so it could be diff too ? Sorry for such a long post, I am so confused right now where to start from but any help is appreciated