DriverSide's Car Dictionary has the most comprehensive definitions of automotive terms. This auto glossary can help you decipher what your mechanic is fixing and what the purpose or function of the particular auto part or accessory is for. We have taken the mystery out of automotive service jargon, so that you don't have to.
The combustion chamber houses thousands of literal explosions per minute, and all of these explosions can leave residue on the spark plug. The color of this residue can tell you a lot about the "quality" of that explosion, and help you verify everything is going on as it should. The buildup of carbon deposits on spark plug electrodes causing the spark plug to misfire, so cleaning and/or replacing them per OEM recommendations is important, especially if your engine seems down on power, and the plugs are due for replacement.