Van, Truck, Trailer, Bus and Coach Aftermarket News in Ireland

Stock up now for glowing winter sales

With winter almost here, so is the peak season for replacing glow plugs. Denso, one of Europe’s leading suppliers of OE quality parts for the aftermarket, reminds installers not to leave it too late to stock up on the best performing cold weather glow plugs, and offers some top tips on glow plug replacement.


Glow plug failure is highest during colder weather when the temperature drops – in fact 80% of replacement glow plug demand occurs between September and March. Knowing this, and building stock levels large enough to handle the inevitable winter demand, will help garages to deliver unbeatable customer service. End-users will also benefit, safe in the knowledge that their diesel vehicle will start, even during the coldest time of the year.

Denso Aftermarket UK & Ireland Product Manager, Nick Thomas explains: “Glow plugs have a vital role to play within the diesel engine. However, glow plugs come under immense pressure to perform in the winter months, with low temperatures, rain and frost all contributing to the increased probability of failure. Installers therefore need to ensure they arm themselves with increased stock levels now, to enable them to provide the right parts when they are needed most. Above this, we also recommend that they look at ways to educate their customer on when and why glow plugs should be replaced. In doing so they will demonstrate a commitment to their customers, which will offer vital peace of mind. This in turn will improve customer loyalty, and ultimately increase profitability.”

Although there are several different types of glow plug on the market, to ensure optimum ignition performance after replacement it is vital to know which technologies perform particularly well in colder weather.

Nick confirms: “In winter there are two types of glow plug that can be particularly recommended for diesel cars: Ceramic and Instant Heating. These technologies provide an extremely reliable, rapid cold start, especially in winter.”

“Instant heating glow plugs in particular are likely to become more prevalent in the future, both as original equipment and in the aftermarket,” he adds. “Denso’s Instant Heating Glow Plugs even offer a unique advantage – with a heat-up time of around two seconds they achieve the fastest start of any glow plugs in the world.”

Nick continues: “This unique advantage reflects the significant changes in glow plug technology in recent years. Whilst all these changes have a positive impact on vehicle performance, the demands on installers have also changed meaning that keeping up-to-date on technology has never been more important.”

Top tips for installers to ensure optimum Glow Plug performance

Make sure you carry out a resistance check on new Glow Plugs before fitting.
When installing new Glow Plugs double check the correct torque requirement – and do not over tighten!
Check all the electrical connections and earths to ensure they are clean and free from corrosion
Use Ohm’s law to check the operating system. In doing so you can check for initial peaks in the amp reading, and also the subsequent drop as the regulating coil takes effect.
Finally, check the vehicle injectors to ensure that they are operating correctly to avoid issues such as poor start-up performance.

He also advises: “Failure to carry out a complete check can ultimately lead to glow plug failure and, in some cases, an overloading of the regulating coil. If this occurs the coil can fracture and debris can fall into the combustion chamber causing extensive damage to the engine. Put simply, we can no longer assume that by fitting new glow plugs all starting problems will be solved. The system is much more complicated than this and it is vital that installers understand this.”