If your issue is the same as mine (chatter under light load between 2000-2500 rpm) then GM says it is the wastegates, and that it is a normal behavior of their vacuum actuated assembly. They released a TSB in 01/16 that addresses it. It basically sounds like something is rattling around in the exhaust. Highly annoying.
I replaced the first car because of it. The new one does it too. I then went back to the dealership and drove a manual off the lot to see if it did it as well. It did, however it was more faint. This is in line with my experience- it starts out very faint and by 1500 miles it gets to full volume.
If I go to 50% throttle or more it disappears, and 15% or less it disappears. The regional field engineer and service dept have no answers except "drive it in tour mode, it's quieter then", as if that is an acceptable resolution!
I replaced the first car because of it. The new one does it too. I then went back to the dealership and drove a manual off the lot to see if it did it as well. It did, however it was more faint. This is in line with my experience- it starts out very faint and by 1500 miles it gets to full volume.
If I go to 50% throttle or more it disappears, and 15% or less it disappears. The regional field engineer and service dept have no answers except "drive it in tour mode, it's quieter then", as if that is an acceptable resolution!
