It is in the combustion chamber of any Internal Combustion Engine where the energy trapped inside the fuel is released, turning the crankshaft and propelling our cars. As the name suggests, a combustion will need to happen and it needs to be done at the right moment. Both, Spark and Glow Plugs are crucial for this process. They look rather similar, their names resemble each other. But what is the difference, and could you use one instead of the other?
The short answer is that each has a very specific and different purpose and can’t be used interchangeable. While petrol engines require spark plugs to ignite the fuel-air mix, Diesel engines depend on glow plugs. The former is required to give off a spark for every combustion triggered in the combustion chamber. Some spark plugs have split electrodes. This way, the spark may also split and ignite more fuel, thus producing a more powerful combustion. Eventually, spark plugs wear out get dirty and may loose their spark. Exchanging them at the prescribed intervals will ensure powerful torque.
Diesel engines work on a different principle, whereby the pressure of the piston compressing the fuel and remaining heat in the combustion chamber cause the combustion. A Diesel engine’s glow plug will only be needed to heat up the combustion chamber to cause the combustion on the first revolution. Once a Diesel engine is running, the fuel-air mix will ignite through the sheer power of the compression under heat. The Glow Plugs will then be shut off and are no longer needed. Generally speaking, because Glow Plugs are not being used as much, they last longer.
German Motors and the plugs share some common roots: the invention of both, the spark plug and glow plug is credited to Germany’s Bosch. For over 100 years, these often unseen components have been crucial to propel our vehicles forward. Since their creation, they have also seen vast improvements. For instance, nowadays, glow plugs are also part of sophisticated engine management, giving off an after-glow to provide better energy efficiency in start-stop traffic.
Although Diesel engines are not very commonplace in Malaysia, those driving a Diesel don’t have to worry about the supply of glow plugs as German Motors will be able to provide the recommended plugs when you come in for your service.
