You may want to read some of the experiences of 2011 buyers who are having problems with the 4-cyl engine making noises at startup and stalling. Check out the Edmunds town hall messages.
GM has not been so good about getting a solid fix for the 2011′s as best as I can tell from the posts. Maybe they have gotten in front of the issues with the 2012 but I have not been able to find any press releases or statements saying they have. If I had read the Edmunds board before buying my Equinox 3 months ago I would be avoiding the nightmare I am in now.
† Edmunds.com received the highest numerical score in the proprietary J.D. Power 2014 Third-Party Automotive Website Evaluation Study℠. Results based on responses from 3,381 responses, measuring 14 companies and measures third-party automotive website usefulness among new and used vehicle shoppers. Proprietary study results are based on experiences and perceptions of owners surveyed from January 2014. Your experiences may vary. Visit jdpower.com.