fast99cam

I have a 2010 SS 2.0L turbo, manual trans, 169k miles and are basically having two issues that I need some direction on. First, when I start (or restart) engine, the turbo will be fine the first time at hard acceleration, if I really get on it, it works fine. Once I let off of the gas pedal, any other times, I get no boost at all. If I turn the key off, then accelerate hard, it has boost, but again, once I back off, I have no boost.

The second issue just happens occasionally. I can go days or weeks without it happening, but sometimes it happens all the time. It is while at cruising speeds, (50-60mph) all of a sudden, I hear detonation, look back and the smoke is so bad, I cant even see a car behind me. I can stop after a short while, and have had to put in as much as 3.5 quarts of oil. I literally checked it right before the last time this happened, oil level was full, I went about 5 miles with it smoking and used 3.5 quarts of oil. I was out of town on a trip last week and I had this happen 4-5 times on my trip home, ended up consuming 10+ quarts of oil on a 300 mile trip. This also happened about 6 months ago, then all of a sudden, stopped. I have put about 20k miles on it without incident, then last week, started happening again. I unhooked the pcv valve that leads to the intake tube, it helped some but it did not solve the issue. Any help or direction would be appreciated. Like I said, it does not happen all the time, so it leads me to believe its not the turbo but some other ancillary part or valve or solenoid going bad, clogged, etc. Thanks