The winter season is here! Winter sees the highest replacement of glow plugs throughout the year, due to the high demand placed on them during cold starts. Glow plugs may seem unimportant, however, they are an essential part of any vehicles diesel system and perform many crucial tasks. Not only on initial ignition, but also throughout the complete cycle that mostly goes unnoticed in the background. For this reason glow plugs could be seen as multi-taskers, working with all new and current fuel-efficient technologies including stop-start vehicles.

Bosch pioneering technologies

Groundbreaking inventions, such as common rail and unit injector systems, makes Bosch a driving force for the continuing progression of diesel engineering. Bosch has almost 100 years of know-how experience working with the latest glow plug developments and technologies.

Glow plugs take on several important tasks

New innovative lower compression diesel engines have an increased reliance on modern glow systems. Due to the lower compression and the reduced temperature in the cylinder, the diesel/ air mixture can struggle to ignite in the case of a cold engine. Thus, the glow plugs play a vital role in the ignition process. Also, when the engine is running, other functions such as post glow and periodic regeneration of the diesel particulate filter are carried out to improve engine efficiency.

Post glow: effective emissions reduction

Originally glow plugs were only used for preheating during the initial ignition. However, with modern direct-injection engines, post glow becomes more essential than ever. It allows the engine to run in a comfortable, quieter and fuel-efficient manner, even in the case of stop-start or city traffic. After the initial pre-heating phase, the glow plug continues to glow for up to 360 seconds and is regulated by pulse width modulation for a higher degree of temperature accuracy. This prevents troublesome “knocking” during cold starts and reduces pollutant content of exhaust gases by up to 60%.

Did you know? Glow plugs should be checked between 50,000 – 65,000 miles and should be changed if necessary. This will prevent future unexpected, costly and inconvenient repairs.

Smoother and faster start-up

The development of Duraspeed technology means glow plugs can be heated to 1000ᵒC in 1.4 seconds, which is half the speed of the previous generation. Also, Duraspeed can reach a maximum glowing temperature of 1350ᵒC, this enables the glow plug to perform its important tasks smoothly even through cold starts in the winter months.

Did you know? If you’re replacing a glow plug, it might seem appealing to go for a cheaper option. However, due to advancements in technology, cheaper plugs do not have the required capability and could possibly do more harm than good to the engine, causing costly repairs.

Periodic Regeneration of the diesel particulate filter

Modern diesel particulate filters can separate almost all soot particles from the exhaust gases. This prevents the release of harmful smoke from the exhaust. However, the filter has a finite capacity and could eventually become blocked, causing excessive back pressure which decreases engine performance and can even cause engine damage. To prevent this, the vehicle performs a periodic regeneration of the diesel particulate filter. With the support from extra fuel being injected and the glow system, temperatures inside the diesel particulate filter rise to the point where excess soot can be burnt off.

Did you know? After the first glow plug breaks the others wont be far behind. For the customer, replacing the complete set is more costeffective and convenient than replacing individually defective glow plugs.

These 3 tasks play an important role in assisting the diesel engine to run more smoothly, efficiently and economically. If any of the following symptoms are left untreated this could cause costly engine damage:

– Longer than usual start-ups – Increased smoke formation, especially after cold starts

– Loud combustion noise before reaching operating temperature “Knocking”

– Decrease in power and/or increased fuel consumption

– Uneven running despite a warm engine Glow plugs are more important than you may think, so make sure you don’t forget to get them checked.