Glow Plug Warning Light and Systems

Glow Plug Warning Light and Systems

One of the most important – but often overlooked – elements of any Diesel engine is the Glow Plug. Whilst incredibly significant to the starting, operation and economy of a Diesel engine, most maintenance and servicing of Diesel engines in Mercedes Vito, Mercedes Sprinter and other Diesel powered vehicles will neglect the inspection and replacement of the Glow Plug.

A Glow Plug is essentially a heating element that heats the fuel and air within a diesel engine, combusting the fuel and encouraging the efficient running of a diesel engine. Glow Plugs are placed in lieu of Spark Plugs – found in petrol powered engines – due to the compressive nature of diesel engines.

Once the heating process has finished, the above light will disappear from your dash and you will be ready to start the engine. During starting and for the first couple of minutes of operation, the Glow Plugs will stay heated to ensure efficient fuel combustion and reduced noise while the rest of the engine warms up.


If your vehicle is experiencing trouble starting on cold mornings (eg, taking a long time between turning the key and starting), chances are that your Glow Plugs are in need of replacement.

If you see the above Glow Plug warning light on your dash even after the initial starting process of your engine – or it appears after minutes of driving – it is very important that you have your Glow Plugs inspected by Eurostar Diesels at your earliest convenience.

If you have more questions about Glow Plug Warning Lights, Glow Plug operation or fuel economy in your Mercedes Van, book an appointment or get in contact with us today!