7 Signs You Need to Replace Your Spark Plugs

The spark plug is responsible for creating the electricity that ignites the air-fuel mixture in the combustion engine, which starts your car. The plugs set the engine’s pistons in motion and continue to provide power to keep your vehicle moving down the road. Appropriate and timely maintenance not only improves the longevity of your vehicle, but it also creates a better driving experience.

If you forget to take your car in for a regular tune-up, it may begin to show signs that it needs some attention. Here are seven symptoms that let you know it’s time to replace your spark plugs.

1. The car is hard to start

The battery is often blamed as the culprit for a vehicle not starting. But spark plugs can just as easily be the cause. Your car’s engine needs to work harder to compensate for worn or clogged spark plugs. It may be particularly difficult to start your vehicle if the weather conditions are harsh. There’s just not enough spark to turn the engine over.

2. The engine misfires

There may be other reasons why the engine misfires, like a bad ignition coil plug cap or inferior quality fuel. However, a misfire is often the result of at least one worn spark plug. You’ll notice the engine pace falters and then catches back up. You may also hear the engine pop as it loses and regains timing. When the vehicle misfires, it sends raw fuel into the exhaust, which ultimately damages the catalytic converter.

3. The car gets poor fuel economy

Worn spark plugs create extra work for your engine. In essence, they’re “not able to effectively burn the fuel” in the combustion chamber. You’ll feel the results of deteriorated plugs in your wallet as you shell out more for fuel.

4. Rough engine idle

If you notice knocking or rattling noises coming from your engine, it’s definitely time to get the spark plugs checked.

5. Your car struggles to accelerate

A worn spark plug is no longer effective at creating the spark necessary to ignite the fuel-air mixture in the combustion chamber. One of the most obvious places you’ll see this lack of energy is when the car struggles to accelerate properly.

6. The engine is really loud

Whether you drive a vehicle with a four-, six-, or eight-cylinder engine, you’ll notice when at least one of the spark plugs is malfunctioning by the noise. Reducing the effectiveness of a cylinder overworks the others and can create strange noises, like rattling.

7. Your ‘check engine’ light is on

Even if you forget to get your vehicle in for scheduled maintenance, its system is finely tuned to alert you to potential problems. Pay attention to the check engine light. It’s a preemptive warning telling you it’s time to take action.

Frequency of replacing spark plugs

The good news is that even with nickel-chromium plugs, you should only have to replace them every 20,000 to 30,000 miles. Noble metal plugs, on the other hand, can carry you past 100,000 miles.

The key takeaway is to pay attention to your car’s early warning signs. It’s easy to overlook a routine maintenance appointment. However, when your vehicle reminds you, it’s in your best interest to heed the advice. One thing you can bank on: Failing spark plugs can add up to costly repairs.