If your Mercedes-Benz is having problems with its glow plug timer relay, it’s best to bring it to a professional mechanic. In this article, we will talk about what a glow plug is, what it does, how you can tell the glow plug is malfunctioning, and how to fix the problem.
What is a Glow Plug and What Does it Do?
Diesel engines have glow plugs instead of spark plugs. It is the heating element that starts the diesel engine. As an electric current passes through the glow plug, it causes the temperature of the fuel and air mixture to rise and helps with ignition.
Locating the Glow Plug
You will find a glow plug in each cylinder of the engine. It will either be in the pre-chamber or the combustion chamber. A glow plug control unit is used to convert information from the engine control unit (ECU) into directions for the glow plugs.
Symptoms Of A Problematic Glow Plug
- Engine Doesn’t Want to Start: Since the job of the glow plug is to produce heat so that the engine can start, if there is an issue with these plugs, your Mercedes will have problems starting. You may notice this is especially worse on cold mornings.
- Misfiring Engine: If you notice a loss of power in your Mercedes-Benz, you may want to have the glow plugs inspected. Since these components are responsible for providing heat for the diesel combustion, if they are not working as intended, the engine will misfire, and you will notice an inability to accelerate and decreased fuel efficiency.
- Rough Idling: When there is uneven ignition because the air did not heat up to the intended temperature, your car may experience rough idling. This happens when the glow plug is not working properly.
- Bad Fuel Mileage: A malfunctioning glow plug will fail to generate the required heat in the combustion chamber, causing the engine to work harder. This will lead to decreased fuel efficiency.
- White Exhaust Smoke: If you notice white exhaust smoke coming out of the tailpipe of your Mercedes, have a professional check the glow plugs. A defective glow plug can leak diesel into the exhaust pipe. When this leaked fuel burns it creates white smoke. You will notice the smoke disappears within a few minutes. However, that does not mean the problem has gone away.
- Check Engine Light (CIL): If your car’s onboard computer detects issues in the circuits, signals, or timing of the glow plugs, this light may turn on. However, if the check engine light (CIL) turns on, it could mean any number of problems with your engine. The only way to uncover the exact problem is to have a professional mechanic attach a scanner to your Mercedes. Once he reads the error codes, he can diagnose what the problem is.
What To Do If You Have A Glow Plug Timer Relay Failure?
- Get It Diagnosed By A Mechanic: The safest way is to have a professional mechanic run thorough diagnostics of your Mercedes. Testing the glow plugs and timer relay will reveal whether they need to be replaced.
- Replace The Relay: Your mechanic will remove it from the socket and place the multimeter probes across the relay terminals. If there is no continuity, it means the relay is probably not working and needs to be replaced.
- Use High-Quality Parts: Use only OEM (original Equipment Manufacturer) parts, which are made specifically for Mercedes, to ensure everything works as intended.
Regular Maintenance
It cannot be emphasized enough how important it is to have your Mercedes-Benz on a regular maintenance schedule. Many problems can be caught early and mitigated with less cost. We can help you with regular maintenance. It’s not just about glow plugs. There are many other issues that can be addressed during regular maintenance and prolong the life of your car.
Visit Carotech Automotive Today
At Carotech Automotive, our 
highly trained, ASE (Automotive Service Excellence) certified mechanics can take care of your car needs. We service all brands of cars, and we even offer a warranty. Call us to find out more. Better yet, make an appointment and come visit us. We are in Los Angeles, California.
Recent Comments