Last updated on 24th December 1998. A spark plug is a part of the ignition system of a petrol engine.
Spark plugs help to remove the heat generated in the combustion chamber.
Spark plugs are subjected to a lot of wear and tear due to the high pressure and temperature at which they perform. Check the spark plugs regularly as their well being affects the performance of the engine. It is a good practice to replace the spark plugs on your car's engine every 20,000 km or whenever recommended by the manufacturer. The Colour signs Ensure that the spark plug leads are not frayed as this can give rise to starting-trouble and unsatisfactory engine performance. When you inspect spark plugs, look out for the indicators in the table - they will tell you whether your engine is running well.