Well I'm not really sure what it was. I still need a gauge, but I'm thinking it was just me being paranoid. I had just filled the tank, and while I've never known a car to become noticeably more sluggish with a full tank, I think in this instance I was looking for something to be wrong. I don't think I really had a dentist drill sound. Since flushing the coolant my car seems to be healthier and my oil level is maintaining a constant level so I think my turbo is doing alright. In my research I found that the problem you could be having is shaft play, which is pretty much your turbo's impeller moving a little and rubbing on the side of the housing. That busts up the impeller, eats oil and sends little fragments of metal into the intake. You can check for shaft play manually though, so I'd start there.