Engine knocking, or detonation, occurs when fuel in the cylinders ignites unevenly, causing metallic pinging sounds, reduced power, and potential engine damage. Key causes include low-octane fuel, ...

There are many reasons a car makes strange, unusual noises only when it's cold. These sounds could be a warning something is ...

Q: My 2009 Volkswagen Jetta Sportwagen – with a five-speed manual transmission – makes a weird tapping noise. The noise has been there forever, yet the car runs great. I have had the engine looked at.