Spark plugs that haven't been changed for a long time can become one with the cylinder head. Fortunately, it's possible to repair damaged threads instead of scrapping the head. (Photograph by Chris ...

The gap between the center and side electrodes needs to be an exact distance across; otherwise, your plugs won't fire efficiently. Remember: Gap new as well as old spark plugs, even if the package ...

It doesn't matter what type of vehicle you drive or which type of spark plug you're using. If your car has an internal combustion gasoline engine, it has the potential to eject a spark plug — although ...

There are several ways to tell whether or not the spark plugs on your vehicle need to be changed or just adjusted and replaced. How often you replace spark plugs depends on the type of plugs you have.