What do Spark Plugs do?

Spark plugs play a crucial role in the operation of an internal combustion engine. They are responsible for generating the spark that ignites the air-fuel mixture inside the combustion chamber. When the spark plug receives an electrical current from the ignition system, it creates a high-voltage spark that ignites the compressed air-fuel mixture, initiating the combustion process. This controlled explosion generates the power needed to drive the engine. Spark plugs also help dissipate heat from the combustion chamber and prevent fouling. Maintaining clean and properly functioning spark plugs is essential for efficient engine performance, fuel economy, and overall vehicle reliability.

The days when you changed your spark plugs every 15,000 miles has ended. Back in the day, spark plugs really did wear out that often. A couple of things are different now…

First, spark plugs are made of better materials that last longer and they’re designed better. The second reason why spark plugs used to have to be changed in vehicles and other autos was that they were fouled up with carbon deposits. The deposits built up when fuel wasn’t burned completely. With the advent of fuel injection and the demise of the carburetor and with modern engine management and ignition controls, that just doesn’t happen as often.

Engine control computers precisely time when fuel is injected into the engine and when spark plugs fire. Unless something’s wrong, spark plugs just don’t foul like they used to.

Electricity from the battery goes into a coil that allows power to build up to anywhere from 12,000 to 45,000 volts, depending on the vehicle. The engine management computer tells the coil when to release the power to the spark plug. The electricity travels through a wire from the coil to the spark plug. At the tip of the plug, a spark jumps between two electrodes and ignites the gas in the combustion chamber.

Some engines have more than one coil. Coils wear out and need to be replaced occasionally. Also, spark plug wires can wear out and need to be replaced.

Modern engines are delivering more power and better fuel economy all the time. That’s largely credited to fast engine control computers, advanced sensors, electronic ignition and improvements to the lowly spark plug.

It’ll be interesting to see where future developments take us. One last thought: it’s critically important to have the right kind of spark plug for your vehicle. Because engines are designed to run with different internal temperatures, spark plugs have different designs to work properly within those temperatures. The Master Technicians at Auto Care Plus will be able to get the correct plugs for your vehicle. And they’ll be able to advise you on when you should replace your spark plugs as well.

DID YOU KNOW?

The “spark” made by your spark plug is like a tiny bolt of lightning; it’s that powerful. Each time it sparks, a wee bit of material is lost from the electrodes. Over the millions and millions of sparks that happen over the thousands of miles you drive, enough material is lost from the spark plug to affect its performance. That’s one reason they need to be replaced.