Oil cap keeps blowing off
That indicates too much pressure. Could be as simple as a malfunctioning PCV.
I think most oil fill caps are placed and turned to lock in place . Just how much pressure would it take to blow one off the engine . Could this be just as simple as someone not turning the cap .
It would be nice to know if this is a recent problem or has been the case since a used vehicle was acquired .
True, I wasn’t thinking about twist on oil caps. If plastic, possibly the threads are stripped or if it has tabs, the tabs are broken.
Best case, the PCV valve is clogged; worst case your Cruze has bad rings. How many miles are on it and how well has it been maintained? Regular oil changes? Checked the oil regularly and didn’t let the level get low? Hasn’t overheated? Have a compression test done and have your wallet handy. You have a 10 year old car and replacing the rings won’t be cheap.
Is it below freezing where you live and do you take mostly short trips? If so, you may have ice in the PCV system. This will pressurize the crankcase. We had this problem with our Buick Encore, which has the same motor. The solution was longer trips to ensure the condensation boils off.
Nobody replaces piston rings on an old engine unless it’s a DIY project. A professional mechanic would replace the entire engine–most likely with remanufactured–if the rings are worn enough to be a problem. Otherwise, he would tell you to just keep an eye on the oil level and top off as needed.