Spark Plugs Service Video

Spark plugs create the spark that ignites the air and fuel in each cylinder. As they wear, the spark weakens and the engine starts to misfire, idle rough, and burn more fuel.

This video sets a worn plug next to a new one so you can see how the electrodes erode and the gap widens with age. It also shows where the plugs sit on a typical inline and V-style engine.

A rough idle at a stoplight is often the first sign, as one cylinder skips a beat. A check engine light with a P0300-series misfire code is another, and so are hard starts and slower acceleration.

Our technicians scan for stored and pending misfire codes, then inspect the old plugs, coils, and boots. A plug that comes out oil-fouled or carbon-fouled points to a deeper problem, not just a worn part. When the plugs are due, our tune-up and spark plug replacement service covers the full process.

A worn spark plug requires more voltage to create a spark across its widened gap. During Frederick County's coldest weeks, this extra demand can make an already worn spark plug cause hard starting. Drivers from Urbana and Walkersville bring us plugs that cranked fine all summer and then would not catch one morning.

If your engine idles rough or the check engine light is flashing, call Spectra Auto Services at (301) 695-5990, or visit your local mechanic in Frederick County to have the plugs checked.