And as a general rule, we recommend replacing spark plugs every 30,000 miles, which falls in line with most manufacturers' recommendations. You can check your owner's manual or the manufacturer's website for information specific to your make and model vehicle.
What are the symptoms of bad spark plugs?
Here is a closer look at how bad spark plugs can cause each of the symptoms.
- Misfiring Motor. An engine will misfire when bad spark plugs delay the combustion effect. ...
- Engine Knocking. Sometimes, especially while accelerating, you will hear your engine making a distinct knocking sound. ...
- Rough Idling. ...
- Hard-Starting Engine.
How long should spark plugs last?
When your engine is functioning correctly, spark plugs should last between 20,000 and 30,000 miles. The U.S. Federal Highway Administration clocks Americans' average annual mileage at 13,476. Break this down into spark-plug life expectancy, and it comes to between 1.5 and 2.25 years.
