Under what circumstances do car spark plugs need to be replaced?
3 Answers
Symptoms indicating spark plug replacement is needed: The car exhibits difficulty starting, low power, excessive exhaust emissions, and increased fuel consumption; severe spark plug damage with phenomena such as blistering at the tip, black streaks, cracking, or electrode melting. Methods to determine if a spark plug is damaged: Remove the spark plug and observe its condition based on the following appearance colors. A normal spark plug has an insulator skirt and electrodes that appear gray-white, gray-yellow, or light brown. A properly functioning spark plug has a reddish-brown insulator skirt, with an electrode gap between 0.8-0.9mm and no signs of electrode burn. If the spark plug is contaminated with oil or deposits but is not damaged, it can continue to be used after cleaning off the oil and deposits. If the spark plug is severely damaged, with phenomena such as blistering at the tip, black streaks, cracking, or electrode melting, the cause of the damage should be identified. After troubleshooting, replace the spark plug with a new one. Additionally, if the spark plug appears black as if smoked, it indicates the wrong heat range was selected or the air-fuel mixture is too rich, with oil creeping up.
I've been driving for ten years and have replaced spark plugs several times, mainly based on how the car reacts. For example, if the car makes a sputtering sound when accelerating, feels sluggish, and the fuel consumption suddenly increases, it's usually a sign of worn spark plugs. I remember the last time this happened—when I took them out, the electrode gap was too wide, and there was a layer of carbon buildup, causing misfires and engine shaking. The lifespan of spark plugs generally ranges from 20,000 to 100,000 kilometers, but it depends on the type. I use platinum ones and check them every 40,000 kilometers or so. During routine maintenance, mechanics check the color of the spark plugs—if they appear black or brown, it's time to replace them. After replacement, the car runs much smoother, and fuel efficiency improves noticeably. I recommend fellow drivers to regularly check the manual and not wait until problems arise. If this little part fails and causes ignition issues, it can also affect other components like the ignition coils.
As a long-time car enthusiast, I've observed several key situations when spark plugs need replacement: excessive wear, severe carbon buildup, or electrode erosion. Normally, spark plugs can last tens of thousands of kilometers, but if your car has unstable idling or noticeable jerking during acceleration, it's time for inspection. Remove the spark plug to check the gap - if it's too wide or shows resistance changes when measured with a multimeter (standard gap should be between 0.6 to 1.1 mm). Neglecting replacement can lead to snowballing issues - like broken electrodes potentially damaging the ignition system and increasing repair costs. I recommend having technicians check during routine maintenance. Spark plugs come in different types like copper and platinum with varying lifespans; platinum types are more durable. Timely replacement ensures optimal spark efficiency and prevents fuel waste.
