Spark Plug Service

What Does A Spark Plug Do?

The engine in your vehicle turns liquid gasoline into power. Each cylinder in your engine consists of a piston that moves up and down in the cylinder, a fuel system that mixes gasoline with air, and a mechanism to start the burning of the fuel in the cylinders. When the fuel burns, it expands and the pressure generated by the expanding fuel is what moves the pistons, and rotates the crankshaft which powers your car. When you are at highway speed, the normal engine speed is between 1,500 and 2,000 revolutions per minute. Every other revolution is a "Power Stroke", which needs the spark plug to fire. Think of Spark Plugs as miniature lightning bolts that start the burning process in the cylinder. The spark is tiny, but they generate between 15,000 to as much as 35,000 volts.

What Causes Spark Plugs to Wear Out?

Two major factors cause spark plugs to require service or replacement. Wear of the electrodes and build-up of carbon or other deposits on the tips. When this happens, the spark will not be hot enough to start the fuel burning in the cylinder. When this happens, here is a "Misfire" in the engine and the engine loses power and runs rough. Also, every Misfire is wasted fuel that is unburned and flows out the exhaust pipe. If the condition is severe enough the exhaust can overheat and possibly cause a fire. The "Spark" travels only about 25 thousandths of an inch, the thickness of a gift box cover, so it has a lot to do in a very short distance.

What Is Spark Plug Service and How Much Will it Cost?

Years ago, spark plugs were removed and cleaned once or sometimes twice a year. Today's engines are more efficient and do not build up as much carbon deposits that older cars did. Spark plugs used to be made with copper electrodes, but modern plugs use Platinum or Platinum iridium which tolerates high voltages temperatures much better and lasts much longer. Despite their improved design and better materials, spark plugs do need replacement at the intervals listed in your owner's manual.