I experienced the same. Its been since the last penguin update for us. We had no manual actions in google but automated actions are very common. My site was especially effected because i had several sites with similar content from same database. I was forced to streamline down to one site with one database. I also had to disavow links that may no longer be acceptable to Google's new guidelines. Check out authorship and content canonical's on your site, these are very big factors with Penguin. Its frustrating to go from top 10 to below 50 for us. Lost lots of business because of these changes. Just chasing the dragons tail with Google changing the game with every update.
