What is the replacement interval for spark plugs in the Corolla Hybrid?
2 Answers
Spark plugs in the Corolla Hybrid should be replaced every 100,000 kilometers. Methods to determine if spark plugs are damaged: Remove the spark plugs and observe them. The condition of the spark plugs can be judged based on their appearance and color. Normal spark plugs have a skirt and electrodes that appear gray-white, gray-yellow, or light brown. A properly functioning spark plug has a skirt that is reddish-brown, with an electrode gap between 0.8-0.9mm and no signs of electrode burn. If the spark plugs are covered in oil or deposits but are not damaged, they can continue to be used after cleaning off the oil and deposits. If the spark plugs are severely damaged, showing signs such as blistering at the top, black streaks, cracks, or melted electrodes, the cause of the damage should be identified. After troubleshooting, replace the spark plugs with new ones. Additionally, if the spark plugs appear black as if smoked, it indicates that the wrong heat range was selected, the mixture is too rich, or oil is leaking into the combustion chamber.
Having repaired cars for decades, I've seen common spark plug issues with the Corolla Hybrid. The manufacturer's manual states replacement at 100,000 km, but the hybrid engine's frequent start-stop cycles put heavy load on the ignition system, so practical advice is to inspect or replace every 80,000 km. Most hybrid spark plugs use durable iridium material, though urban stop-and-go driving reduces lifespan. If owners notice weak acceleration, idle vibration, or sudden fuel consumption increase, these could be spark plug warning signs. During routine maintenance, don't just change oil - visual inspection of spark plugs every two years prevents major repairs. A set costs around a hundred bucks, not expensive but safety comes first.
