I have a 2012 cruze 1.4 manual. A while back I had an issue where the car would bounce rpms a little, and over time for progressively worse to where it wouldn't idle. I replaced the valve cover and it seemed to have fixed everything. But a couple months later I'm having the same issue, and now it's kind of rough on start up. Is there something that could be causing my valve cover to go bad so fast?