That rhythmic knock under the hood could mean five very different things.

Add Yahoo as a preferred source to see more of our stories on Google. Your engine can make a lot of weird noises, depending on what has gone or is about to go fully kaput. If it's a rhythmic pinging ...

Cars are complex machines, and as a result, it's not always evident what's going on under the hood — especially if something is wrong. With all the various components of your car working in harmony, ...