cache in 2.2.2 not starting?

Cache doesnt’ seem to be kicking in for me version 2.2.2. I had issues where my previous cache was interfering and deleted the wp-content > cache folder (which provided a cure). Is there a new setting somewhere in this version of WP that I need to define as true, or click to get started? In the past it seemed to work right away for me. Thank you!