Bought my car about 2 months ago. First noticed 1 month ago the pipe/hose leading from the rear portion of the inter cooler to the turbo (forgive me, still learning the parts...inlet hose? please correct me), wasn't fitting properly and there was a small buildup of black residue around the area. I was told by a few people not to worry about it and that it wasn't a big concern, that it's caused by the heat making the hose expand/contract etc. My logic is telling me that it should be a concern. I undid the screw clamp and the pipe didn't budge any farther up the turbo, there just wasn't enough slack. The clamp is on there as tight as it will go, so it's not loose from what I can see. Tried to unfasten the screw clamp on the other end that connects to intercooler but couldn't get my hand up in there with enough torque. I started to notice recently more lag esp around 3-4k. Not to mention the black residue. Could be paranoia and the fact that I need to change my oil. I guess what my main questions are...
1.) What exactly is the technical term for this pipe/hose?
2.) I think it's obvious that it needs to be fixed, is this a dealer part or a part I would be better off buying after market?
3.) What kind of damage can be caused by this problem? (just so I know)
4.) Is the residue oil from the turbo? And what is causing it?
5.) Just a side question, what fluid is the dipstick located under the rear of the intercooler for? (car didn't come with a manual...err)
Checked for Haynes and Chilton on the 05 WRX and they don't seem to make them. I know there is one other manual...Bennet I believe? But internet searches don't show anything for it.