How can you tell when a spark plug is bad?

A spark plug is a small, cylindrical device that is used to create an electric spark in the engine of a vehicle. The electric spark helps ignite the fuel and air mixture in the engine, which then creates the power to move the vehicle. Spark plugs typically last around 30,000 miles before they need to be replaced. However, there are several ways that you can tell when a spark plug is bad and needs to be replaced.

One way to tell if a spark plug is bad is by its appearance. If the electrode at the top of the plug looks black or covered in carbon deposits, then it may be time for a new one. Another sign that a spark plug needs replacement is if it’s misfiring or not firing at all; this can often be detected by your car’s check engine light coming on. You can also test your plugs yourself by removing them from your car and checking their resistance with an ohmmeter; if they’re below 1 kΩ (which indicates that they’re no longer functioning properly), then it’s time for new ones.

If you’re experiencing any of these symptoms – poor performance, misfiring, check engine light – it’s likely time for new spark plugs regardless of how many miles are on them!


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