When it comes to diesel engines, glow plugs play a crucial role in the starting process, especially in colder temperatures. The glow plug relay is an integral component of this system, responsible for delivering power to the glow plugs at the right moment. However, like any other electrical component, the glow plug relay can fail over time, leading to various issues.
Causes of Glow Plug Relay Failure
- Wear and Tear: Over time, the internal components of the glow plug relay can wear out due to continuous usage. This wear and tear can lead to electrical malfunctions, resulting in the failure of the relay.
- Corrosion: Exposure to moisture and other environmental factors can cause corrosion to build up on the relay’s connectors or terminals. Corrosion disrupts the electrical flow, leading to relay failure.
- Overheating: Continuous exposure to high temperatures under the hood can cause the relay to overheat. Excessive heat can damage the relay’s internal circuitry and lead to failure.
- Voltage Surges: Electrical surges or voltage spikes can occur due to faulty alternators or improper jump-starting procedures. These surges can damage the glow plug relay, rendering it ineffective.
Symptoms of Glow Plug Relay Failure
- Difficulty in Starting: A failing glow plug relay may cause difficulty in starting the engine, especially in cold weather conditions. The engine may crank for a longer time before it eventually starts.
- Engine Misfires: When the glow plug relay fails, the glow plugs may not receive sufficient power to heat up properly. This can result in incomplete combustion, leading to engine misfires and rough idling.
- Poor Fuel Efficiency: A malfunctioning glow plug relay can cause inefficient combustion, resulting in decreased fuel efficiency. You may notice a significant drop in your Mercedes’ mileage.
- Check Engine Light: In some cases, a failing glow plug relay can trigger the check engine light on the dashboard. The onboard diagnostics system may detect a problem with the glow plug circuit and alert the driver.
Solutions for Glow Plug Relay Failure
- Relay Replacement: If your Mercedes is exhibiting the aforementioned symptoms and the glow plug relay is diagnosed as the culprit, replacing the faulty relay is the most common solution. Ensure that you use a genuine Mercedes glow plug relay for optimal performance and reliability.
- Electrical Inspection: Before replacing the relay, it is important to inspect the entire electrical system associated with the glow plugs. Check for any loose connections, damaged wiring, or corroded terminals. Repair or replace any faulty components as necessary.
- Battery Health: Ensure that your vehicle’s battery is in good condition and providing sufficient power. Weak or low-voltage batteries can strain the glow plug relay and lead to premature failure. Consider having the battery tested and replaced if necessary.
- Preventative Maintenance: To prolong the life of your glow plug relay and the overall health of your diesel engine, it is essential to follow the manufacturer’s recommended maintenance schedule. Regularly inspect and clean the glow plugs, and address any issues promptly.
Enjoy The Optimal Performance From Your Mercedes
A failing glow plug relay can cause significant issues in the starting and running of your Mercedes diesel engine. Recognizing the symptoms early on and taking appropriate measures can help prevent further damage and ensure smooth operation.
If you are uncertain about diagnosing or repairing the glow plug relay yourself, it is advisable to seek professional assistance from one of our qualified mechanics. By addressing the issue promptly, you can avoid potential engine damage and enjoy optimal performance from your Mercedes.
Book An Appointment With Hagan’s Motor Pool Today
If you have a Mercedes vehicle and have been 
experiencing trouble with your Glow Plug Relay, then Hagan’s Motor Pool is the place to go. Located in Rochester, NH, our team of knowledgeable and experienced technicians can quickly diagnose the issue and fix it in no time.
We understand that a malfunctioning Glow Plug Relay can lead to frustrating experiences with your car. We offer appointments for your convenience, so you can have your Mercedes performing at its best in no time. We also proudly service customers from the surrounding areas of Alton, Barrington, Berwick, and Dover. Contact us today to book an appointment.