Considering purchasing a 2011-2012 model year Acadia or Enclave and have started to research whether there are any significant issues with the 3.6L VVT Direct Inject engines or trans axles. I didn't do my homework a few years back on the GM 2.4L DI engines used in the Equinox and Terrain models. LOTS of problems with the earlier years. Particularly interested in longevity, oil consumption, timing or balance chain, and direct inject issues. I have a 2003 Envoy I6 with 218K miles so I'm what you call a buy and hold owner. Thanks for any insight you can offer.