When Do the Spark Plugs Need to Be Changed?

The spark plugs should be replaced every 30,000 miles. However, modern automobiles have the ability to last longer than that. You may not even need to change your spark plugs until you’ve driven 100,000 miles. Here are some signs your spark plugs may need to be replaced.

Get Ready for Some Rough Starts

To get your car, truck or utility vehicle to start, you must have fuel and air in each cylinder. The starter transmits electricity to the spark plugs when you press the start button or turn the ignition key. Each cylinder has a spark plug. It will be difficult for your car to start if one or more spark plugs stop producing sparks.


This is where you get the phrase “firing all cylinders”. Your engine will not fire correctly if there are a few cylinders which aren’t firing due to worn plugs. Unfortunately, when the timing reaches the cylinders that cannot fire in the sequence, your engine will cut out briefly. This is what misfiring is. Your engine may stall often due to the misfiring.

Rough Idling

The misfiring will also cause your engine’s idle to be rough. Unfortunately, you will feel your vehicle jerking and you will hear the engine cutting out while you are sitting at an idle. It is easier for the engine to stall when you are sitting at an idle because you do not have the accelerator pressed down.

Acceleration Lag

Your acceleration will also slow down, in addition to the rough idle. Your engine’s performance may actually lag in extreme cases. The vehicle isn’t firing on all cylinders. This causes the engine to not produce enough combustion efficiency to make power.

A Surging Engine

If the spark plugs stop firing properly, your engine might pick up speed unintentionally. It could be the spark plugs, or your engine control unit. This unit controls when the plugs start to fire and the order in which they fire.

Increased Consumption

Spark plugs are essential for fuel economy. Make sure they get changed as soon as possible if you are having engine performance problems. Spark plugs can cause your engine to consume more gasoline and diesel fuel if the engine is not running well.

We’re here to help. Call us today to schedule a service visit for your truck, SUV, or car. We will inspect the spark plugs and replace them if they are worn out

Photo by EkaterinaZakharova from Getty Images via Canva Pro

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