Should the Spark Plugs Be Replaced at 20,000 Kilometers for the New 5 Series?
3 Answers
The spark plugs of the new 5 Series can be replaced at 20,000 kilometers. Under normal maintenance conditions, spark plugs should be replaced after driving 40,000 to 60,000 kilometers. However, this may vary depending on the brand and engine type, so it is recommended to follow the user manual. You can refer to the following standards for maintenance and replacement: platinum spark plugs should be replaced at 40,000 kilometers, ordinary nickel alloy spark plugs at 20,000 kilometers, and iridium spark plugs at 60,000 to 80,000 kilometers. Steps for replacing spark plugs: Open the hood, lift the plastic cover of the engine, remove the high-voltage wires, and mark each cylinder's position to avoid confusion. Use a spark plug socket to remove the spark plugs one by one. While removing them, check for any external debris like leaves or dust and ensure everything is cleaned thoroughly. Place the new spark plugs into the spark plug holes, hand-tighten them a few turns, and then use the socket to tighten them further. Reinstall the high-voltage wires according to the firing order and secure the cover.
During the 20,000 km maintenance of my new 5 Series, the 4S dealership stated this was a mandatory BMW maintenance item. Turbocharged engines require spark plugs to maintain optimal gap clearance, otherwise misfires and vibrations may occur. I inspected the removed old spark plugs, and indeed the electrodes showed signs of erosion, wearing out much faster than in naturally aspirated engines. Not replacing them now could affect ignition efficiency and may increase fuel consumption in the long run. Although paying out-of-pocket costs over a thousand yuan, considering the precision ignition requirements of direct fuel injection systems, this expense truly shouldn't be spared.
As a German car owner, I believe it's necessary to change spark plugs at 20,000 km. The B48/B58 engines have high compression ratios. Although the factory iridium spark plugs are durable, BMW's conservative settings aim to prevent carbon buildup. A friend of mine delayed replacement until 30,000 km and experienced noticeable cold start hesitation. Now I strictly follow the onboard CBS maintenance reminders for self-maintenance, since ignition system repairs are more expensive. For frequent urban driving with start-stop systems, extra attention is needed as spark plugs working long-term in low-temperature conditions wear out faster than expected.
