The glow plugs in your Mercedes typically have a long lifespan. They will go through some wear and tear and naturally meet their end of life. Car owners need to know when the glow plugs are dying out and when the best time is to get those replaced by a qualified mechanic. Some of the most common signs to look for to know whether the glow plugs are damaged or faulty include the below symptoms.
Engine Warning Light
The engine warning light on your dashboard may be the first clue that something is not working well. Any car that displays this light needs to be taken to a reputable auto repair shop to have a mechanic look it over right away. There are several things that may cause the engine warning light to illuminate. This warning light is likely to turn on when any of the other problems with the glow lights happen as well, so always look for a combination of problems.
Hard Starting
When the engine forces a hard start, you are seeing one of the most common signs that the glow plugs are damaged. When conditions get cold, the combustion chamber can struggle to reach the correct temperature to ignite the fuel and make the engine start if the glow plugs do not work. If your engine starts hard and there seems to be no problems with the battery or the fuel, then have a licensed mechanic take a look at the glow plugs.
Engine Misfiring
For the combustion process to happen in diesel engines, two things need to happen: There needs to be a large amount of compression when fuel is added to the area at the right time, and there also should be the correct amount of fuel added. This will ignite the diesel fuel and provide the proper combustion.
Misfires happen when this process does not work as designed. The glow lights may be part of the reason that there isn’t enough power to keep the engine going.
Rough Idling
If you have one or more of the glow plugs burn out on you, or the glow plugs get damaged, then it is much harder to start your engine. This is even more true when the temperatures start to drop and get colder. The mechanic is able to take a look at the glow plugs to see if they are the problem. If these plugs have a little burning on their edges, then the issue may be more about the fuel injection timing instead.
Lower Fuel Efficiency
The fuel and the temperature outside can really determine your fuel efficiency, rather than the glow plugs. However, there are a few situations where the glow plugs will play a role. For example, based on the local climate, diesel can be blended with other additives in the winter to lower its freezing point and make it last longer. The blended fuel often has a lower energy content and will provide a reduced fuel efficiency.
Every Mercedes owner needs to consider adjusting the engine operating temperatures to make sure all of the fuel injected is burned well. Glow plugs can give some additional heat into the chamber to make the fuel efficiency better. If the temperature is not reached because the glow plugs do not work, the performance of the engine will suffer. It may have to work harder in order to meet all of the demands placed on it.
If you suspect that the glow plugs are not 
working on your car, then it is time to take it into our licensed mechanics. We will run diagnostics on your Mercedes and determine what problem is present, whether it is the glow plugs or something else. We will then advise you of the best steps to make sure the glow plugs work properly and not cause you any more problems while you drive.
When it is time to replace your glow plugs on your Mercedes, trust us at Heynneman European. We are happy to help with all of your Mercedes repair needs. Our team proudly serves the area of Larkspur, Kentfield, Cote, Mill Valley, San Anselmo, Fairfax, and San Rafael, CA. Contact us today to get your appointment scheduled. We look forward to meeting you soon.
