What Causes Spark Plugs To Wear Out?
Every time a spark plug creates an arc of electricity, it very minimally shortens the electrodes. Over time, the gap between the electrodes grows larger. As this gap increases, more electricity is needed to spark ignition of the air/fuel mixture. As this happens, the ignition performance deteriorates leading to unstable ignition. Eventually, the gap will grow so large that the spark plug won’t arc at all.
Other causes of spark plug wear include:
- Overheating caused by pre ignition
- Oil contamination
- Carbon/deposit build-up
These will all cause premature wear, but by design, spark plugs are designed to wear out. Continuing to drive with worn spark plugs will shorten the life of your vehicle’s ignition coil.
What Are Symptoms Of Worn Spark Plugs?
Once a spark plug becomes sufficiently worn, it will affect the performance of your engine. Replacing your plugs at the recommended intervals written in your vehicle owner’s manual schedule will virtually eliminate these problems, but a fouled or faulty plug can cause issues.
These are the signs of worn spark plugs:
- Misfiring/Rough Idle: When your spark plugs are worn, you might notice unusual vibrations and noises like rattling or knocking coming from your engine while you’re idling.
- Misfiring/Slow Acceleration: Another sign that your engine is misfiring as a result of worn spark plugs is slow acceleration. When a spark plug doesn’t operate optimally due to being fouled or dirty, it doesn’t spark effectively which causes your car to feel sluggish. You might feel your engine stop, stall, and then stumble to start again.
- High Fuel Consumption: Worn spark plugs can cause your engine to work inefficiently, ultimately leading to increased fuel consumption and emissions.
- Hard Starting: Vehicle struggling to start? A dead battery isn’t always to blame. In order for your engine to start, the spark plugs need to produce a sufficient spark. If your vehicle is particularly difficult to start, worn spark plugs could be the culprit.
If you spot any of these signs, it’s best to ask a professional to check the spark plugs to see if they need to be replaced. You should do this as soon as possible to prevent further damage to your vehicle.
