Does the new BMW 5 Series need spark plug replacement at 20,000 kilometers?
3 Answers
B48-TU generator requires replacement every 20,000 kilometers. The reason is that this version of the engine performs more work cycles per unit time compared to non-TU version engines, hence the recommendation for 20,000 km replacement. For B48 engines (non-TU version), there's no need to replace spark plugs every 20,000 km; they can follow the conventional vehicle maintenance schedule for spark plug replacement (typically every 40,000 km). Spark plugs are crucial components in a gasoline engine's ignition system. They introduce high voltage into the combustion chamber, causing it to jump across the electrode gap to create a spark, thereby igniting the combustible air-fuel mixture in the cylinder. Under high voltage, the air between the spark plug's center electrode and side electrode rapidly ionizes, forming positively charged ions and negatively charged free electrons. When the voltage between electrodes reaches a certain level, the number of ions and electrons in the gas increases like an avalanche, causing the air to lose its insulating properties and forming a discharge channel between the gaps - a phenomenon called "breakdown." At this point, the gas becomes a luminous body, creating a "spark." Accompanying this is thermal expansion and a "crackling" sound. The temperature of this electrical spark can reach 2000-3000°C, sufficient to ignite the air-fuel mixture in the cylinder's combustion chamber.
I just replaced the spark plugs on my BMW 5 Series. For a new car with 20,000 kilometers, the BMW manual clearly recommends replacement. Due to the frequent and precise operation of the new engine, the spark plugs endure high pressure and are prone to wear. Not replacing them in time can affect ignition efficiency, leading to increased fuel consumption, engine vibration, or starting difficulties. I personally noticed much more responsive throttle after the replacement. Long-term neglect can damage the ignition coils and increase repair costs. BMW 4S店 maintenance plans usually cover this, and the cost is reasonable. It's advisable to maintain on schedule to ensure smooth car operation, while also paying attention to driving habits, such as frequent traffic congestion, which may affect spark plug lifespan.
From a mechanic's perspective, the BMW 5 Series should have its spark plugs replaced after running 20,000 kilometers. The engine's high-pressure design causes rapid wear on the spark plugs, and failing to replace them leads to noticeable performance decline: unstable idling, sluggish acceleration, and even the illumination of warning lights. Replacing them brings significant improvement, and since spark plugs are relatively inexpensive, it's a cost-effective way to prevent bigger issues. It's advisable not to delay until 30,000 kilometers, as melted spark plugs could damage the coil, leading to more expensive repairs. Owners can DIY using BMW-specific tools, but must ensure accurate installation to avoid mistakes. Alternatively, taking the car to a familiar repair shop is quicker and more convenient.
