How often should Ford Focus spark plugs be replaced?
2 Answers
According to the Ford Focus spark plug maintenance manual, they should be replaced every 45,000 kilometers or 30 months. Spark plugs have a service life, and prolonged use can lead to carbon buildup. If not replaced regularly, the engine may experience difficulties starting, reduced power, increased fuel consumption, and excessive exhaust emissions. If a spark plug fails, the engine cannot function properly, and the car naturally won't run, necessitating prompt replacement. Additionally, spark plugs should be replaced based on individual driving conditions. If you notice difficulty starting the vehicle or if the spark plugs genuinely need replacement, you can decide to replace them accordingly. Gasoline engines are equipped with spark plugs, one per cylinder, with some high-speed gasoline engines having two spark plugs per cylinder. Although spark plugs are small components, they are extremely important. The function of a spark plug is to introduce the high-voltage pulse generated by the ignition coil into the combustion chamber, using the electrodes to produce a spark that ignites the air-fuel mixture, completing the combustion process. How spark plugs work: The electrode of the spark plug repeatedly generates electricity to ignite the air-fuel mixture in the cylinder. Meanwhile, other parts of the ignition system produce timed high-voltage electrical pulses, creating sparks and explosions that provide the energy required for the engine's power output. The structure of a spark plug consists of a slender metal electrode passing through a ceramic insulator. The lower part of the insulator is surrounded by a metal shell, which is screwed into the cylinder head. The bottom of this metal shell is welded with an electrode to ground the car body. Spark plugs are devices that ignite the gasoline and air mixture entering the engine combustion chamber. Operating under high-temperature and high-pressure conditions, they are one of the vulnerable parts of a gasoline engine. They play a crucial role in the engine's operation, significantly affecting fuel efficiency and smooth running. Precautions for replacing spark plugs: It is best to replace them when the engine is cold. When removing, pull from the base of the high-voltage line, not directly tugging the wire, as this can break the inner core. Also, mark the positions of each cylinder's high-voltage lines before removal to avoid confusion. Before installing new spark plugs, ensure they are compatible with the engine of the vehicle model being serviced.
I've been driving a Focus for five years, and changing the spark plugs is quite particular. The manual recommends replacing them every 30,000 kilometers, but I once tried stretching it to 40,000 kilometers before changing them. The result was slower engine starts and a 10% increase in fuel consumption, but everything smoothed out immediately after replacement. If you mainly commute in the city and drive gently, you might push it to 35,000 kilometers; but if you frequently drive on highways or drive aggressively, it's better to check them earlier. Worn spark plugs accumulate carbon deposits, leading to poor ignition, which can affect engine longevity over time. Replacing them with OEM ones costs just a couple hundred bucks—way cheaper than fixing major issues later. Remember to have the technician check the connectors during maintenance to ensure your car runs smoothly and efficiently.
