Why are the tips of DENSO glow plugs grey/blue in colour?
Alongside many other premium quality products, DENSO is a glow plug manufacturer, supplying them as original equipment (OE) parts, but it also supplies the independent service and repair sector, and as its aftermarket range is produced on the same production lines to the same standards, they can be relied on by automotive technicians and motorists alike.
Although this statement should be enough to reassure those with any concerns over the providence of its glow plugs, to clarify the situation and provide peace of mind for both installers and its valued customers throughout Europe, DENSO is very happy to explain why the tips have this colouration.
In common with many highly engineered products, the manufacture of glow plugs is a complex process, particularly the production of the glow tube, which when installed, can be heated up to temperatures above 800 degrees Celsius within seconds, and is needed to ensure a quick and reliable start when the engine is cold, and to reduce emissions when it is running.
As this heating element is the most critical component of the glow plug and allows it to fulfil its role in the ignition system, its functionality has to be verified during the production process. It is for this reason, that at the end of the production line, the performance of each glow plug is thoroughly tested to ensure that it is working in accordance with the given specification, including its heat-up time and the temperature it needs to reach.
It is this in line production test, that causes the glow plug’s tip to take on this grey/blue tone. This colouration is due to the oxidation of the metal, which is accelerated by the high temperature it is subject to during the test, but it does no harm to the glow plug, nor does it degrade its performance.
Therefore, rather than being something of concern to technicians when opening the box, it should be regarded as a sign of reassurance, because it indicates that the glow plug they are about to fit has been tested and works according to its given specification, and will perform as they’d expect from one of the world’s premier OE automotive parts suppliers.
At the forefront of automotive technology, DENSO’s considerable R&D investment has helped it to pioneer increasingly efficient, powerful and reliable diesel engines with minimal emissions.
DENSO Aftermarket, which naturally draws on this expertise, subsequently offers a comprehensive, OE quality all-makes glow plug programme, that benefits from its cutting-edge technology and provides remarkable start-up performance with extended post-heating temperatures, to deliver a complete competitively priced solution.
For further details of the DENSO glow plug range, visit DENSO Glow Plugs pages and DENSO E-catalogue.