Hello: I have a Toyota Prius 2012 w/ 290,000 miles pretty much. I put in a new gasket not even a year ago from Gasket Masters and worst decision and now I'm starting to hear knocking on my car. Is it worth fixing? I know it's not a good time to buy right now. I live in Cali. Not sure if it's the gasket but what would you do? Any thoughts anyone much appreciated!! Thank you!