How to Deal with a Glow Plug Timer Relay Failure in a Mercedes

Posted on November 24, 2021 by Carson Wileman
Mercedes Glow Plug Warning

Mercedes glow plugs, also known as glow plug timer relays, might have issues that prevent you from enjoying your car to its fullest. Glow plugs are a crucial component of your Mercedes engine since they supply the heat and power required to start the vehicle.

Ignition methods differ depending on the type of engine in your automobile. Glow plugs are used to start a Mercedes diesel engine instead of spark plugs. Unlike the typical spark plugs in gasoline engines, glow plugs give power generated by high temperatures and high-pressure levels to start the engine via engine cylinders.

The Glow Plug Timer Relay

Diesel engines use cylinder pressure and temperature to ignite the fuel mixture rather than spark plugs to start combustion. Glow plugs effectively warm up the engine cylinders to an ideal temperature, leading to effective combustion during cold starts and in cold weather situations since temperatures can be significantly lower. They get their name because when current is applied to them, they glow a vibrant orange hue.

If glow plugs are on for an extended period, the high degree of heat they may create can cause significant damage. Similarly, if they are not powered long enough, there will be insufficient heat to burn the fuel effectively. The glow plugs utilize a glow plug timer relay to overcome this problem, instructing the plugs when to operate and when to stop to safeguard the engine and allow it to run efficiently.

Considering glow plugs are so crucial to your Mercedes performance, their wear and tear must be closely monitored over time. Regrettably, some models have difficulties with glow plug performance, particularly the glow plug timer relay.

Signs of a Glow Plug Timer Relay Failure

The glow plug’s malfunction can come from the glow plugs themselves, the timer relay, or any minor elements that make up these components, such as fuses and wire. The failure signs to watch for can help detect the problem and what steps to take next. The following are some of the signs that may occur:

  • Glow Plug Light Comes On: The glow plug light on your dashboard will most likely activate if your Mercedes glow plug timer relay fails. When the ECU detects a malfunction with the glow plug system, this light in the instrument cluster will illuminate or flash.
  • Engine Light Comes On: An illuminated check engine light is another sign of a problem with the glow plugs or timer. If the computer detects a problem with any of the glow plug’s circuits, signals, or timing, the check engine will illuminate to alert the driver. The light will generally illuminate when the car has begun to have trouble starting.
  • Misfiring Engine: Functioning glow plugs are required to start your engine. If they aren’t working properly, you might encounter difficulties starting your vehicle. Since the glow plug timer relay is required to guarantee that the glow plugs heat up to the ideal temperature during the ignition cycle, if the relay fails, the glow plugs will almost certainly fail as well.

They will turn on at random moments, or worse, they may remain on and cause damage owing to the quantity of heat they create. You should expect more ignition misfires if the glow plug timing is out of cycle since the glow plugs may turn off when they need to be on and vice versa.

Quality Service for Your Mercedes at Keith Cox Autobahn

If you see any of the described symptoms in your Mercedes, the best thing you can do is take it to a reputable mechanic Mercedes Glow Plug who can thoroughly examine and diagnose the problem. The glow plugs and glow plug relay timer can then be tested to see whether they need to be changed.

At Keith Cox Autobahn, we offer the best quality service for your Mercedes. We can run diagnostics for your vehicle in no time and get you back on your way. When it comes to Mercedes repair, maintenance, and diagnostics, we are the specialists.

If you live around Bellingham, WA, and you suspect that your glow plug is defective, feel free to reach out to us. Please call or visit our shop today to schedule an appointment or learn more about our services and maintenance programs.

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