I threw this on the Facebook page, too. I wanted to give a shout out to Advantage Chevy in Bolingbrook, IL. I brought my '13 LT 6A Cruze with 67k miles to the dealer with a cel and a rough running engine. I thought for sure that they would figure out a way to deny that it's covered under the powertrain warranty. So, I'm waiting for the service writer to come to tell me how much it's going to cost. he finds me a couple hours later and says "you're all set, Mike". He showed me the invoice and there were a lot of zeros on it. That was nice. the intake and valve cover had to be replaced and the non return valve was missing. what is a non return valve and how does it come up missing?