My daughter's 97 Civic had its engine replaced recently. Today, as the car went over bumps she saw a light blinking. She thinks it's the check engine light. At the same time, the tachometer would jump 500 or more RPMs, suddenly jump up and down, but she didn't notice the engine increasing in acceleration. I drove the car myself and, as I saw the tachometer increase by 500 to 1000 RPMs and pretty quickly come down, I heard a noise twice. Not big nor long, but as if something was grinding against something. I didn't notice the engine increase in RPMs either. Any idea what this may be? Than you Tony
