[Michigan_S13]

Alright guys so I bought a 91 240sx with the boosted stock block about a month ago. Was running strong at 12 psi when I bought it. Put around 1500 miles on it since then.

Just a few days ago I was driving on the highway and had to make a few passes like a racecar driver so I downshifted. Went from like 55 to 90 mph from 3000~5500ish and then when right as I shifted back to fifth I heard a quietish, but louder than the average afterfire popping sound and saw white smoke puff out of the exhaust and there was also the classic burnt oil smell.

I looked over the head gasket and it was fine. Coolant is fine. Oil is a little overfilled which could have played a part in it. I can hear the turbine in the turbo is a bit off track which results in cringes when I forget to shift before the turbo tries to kick in. It's not terribly loud, not like you can hear it sending metal through shit. Just small clicks like it's tapping metal repeatedly.The vacuum is good at idle and while driving, and when the turbo kicks in it hits up to 3 pounds of boost and just sticks there. The car runs and drives great when you shift like a pussy. Just wanna figure this out so I can spool at some sexy hoes.

This is my first turbo'd car, which I may be dumb for choosing the KA but I'm actually quite excited to fix this shit on my own and learn some things. Plus the torque leaves a smile on my face every time drive it.
Obviously I'm going to replace the turbo and run a check for boost leaks afterwards. I'll also change the oil, oil filter and air filter while I'm at it.

So basically the point of this thread is what's up zilvia, tell me if I've got the right idea or if I'm a dumbass, and make some suggestions if you have anything else you think I should check. Like I said this is my first turbod car, don't have much experience but Im super determined to fix it, and hopefully I'lll learn a few things from you guys while I'm on this forum.