What type of spark plugs can indicate a problem with engine performance?

A carbon-fouled spark plug is a clear indicator of potential engine performance issues. When a spark plug becomes carbon-fouled, it typically shows signs of excessive carbon buildup on its surface, which can be a result of incomplete combustion. This buildup can affect the spark plug's ability to create a spark effectively, leading to misfires, rough idling, difficulty starting the engine, and reduced overall power output.

In addition to misfiring, carbon fouling can point to several underlying problems, such as:

• An overly rich fuel-air mixture, which results from too much fuel or not enough air entering the combustion chamber.

• A malfunctioning fuel injector that may be delivering excessive fuel.

• Poor ignition timing or weak ignition components that fail to ignite the air-fuel mixture completely.

By diagnosing and addressing the carbon fouling of spark plugs, mechanics can often identify and resolve the root causes of poor engine performance, improving efficiency and reliability. Thus, monitoring the condition of spark plugs, particularly for carbon fouling, is crucial for maintaining optimal engine function.