2023 Mercedes-Benz GLE350 Has Rough Idle

Causes of Rough Idle in 2023 Mercedes-Benz GLE350 and Solutions for Smooth Performance

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Reviewed by
Andrew Hajjar
Written by RepairPal Car Genius
Updated January 14, 2025
0%
21% chance it's the
Spark Plugs
0%
15% chance it's the
Ignition Coil
0%
64% chance it's
Something else
The most common reasons a 2023 Mercedes-Benz GLE350 has rough idle are a vacuum leak, an issue with the spark plugs, or a problem with the ignition coil.
  • Spark Plugs: Worn or fouled spark plugs can lead to misfires, poor fuel economy, and difficulty starting the engine.
  • Ignition Coil: A faulty ignition coil can cause misfires, rough idling, and difficulty starting the engine due to inadequate spark delivery to the spark plugs.
Proper diagnosis will determine the exact cause of your symptom, saving you money on unnecessary repairs. The diagnostic experts at RepairPal Certified shops have the right tools and experience to solve any symptom.

How much does it cost to fix a 2023 Mercedes-Benz GLE350 has rough idle?

Common Repairs

The total repair cost will vary based on the condition of your vehicle and the number of repairs needed to fix your symptom. Proper diagnosis will save you money by finding the exact repairs needed to fix your car right the first time.

Brake caliper failure occurs in two different ways, and they create different symptoms.

The caliper can become stuck, in which case it won't release the brake pads. The seized caliper will cause the vehicle to brake constantly on one side, forcing the car to move toward that side. This pulling will be accompanied by a strong odor from one wheel.

Another way calipers fail is by leaking. If the caliper leaks, the brake pedal will feel too easy to push, and will sink all the way to the floor when held. Braking will become less effective the longer this goes on. There may also be brake fluid leaking onto the wheel.

Here are a few common symptoms of worn-out brake pads:

  1. Low brake pad warning light is on: Not all vehicles are equipped with this system, but if yours is, this dashboard indicator light will likely be the first signal it’s time to replace your brake pads.
  2. Brakes start to squeal regularly: This is often one of the first signs of worn brake pads and is caused by a metallic piece built into brake pads for this exact purpose. This part contacts the brake rotor to make a squealing or whining noise when the pads are low.
  3. Brakes make loud grinding noise: If not addressed early enough, your brake pads may get so worn that the metal backing plate of the pad grinds against the metal rotor.
  4. Brake pads look thin: You may be able to visually check your brake pad thickness to determine if they need replacement.

Brake rotors are mainly maintenance free, but when they have been subjected to abnormally hard use, the heat they absorb can cause the metal to turn blue, and cracking to occur. When this occurs, customers often specify they have lost braking power, or the vehicle's brakes are making noise. There may be no symptoms at all related to changing the brake rotors, since it is recommended to change brake rotors on most modern vehicles when performing a standard brake service.

Most often, a brake system inspection will just be a routine portion of manufacturer specified maintenance, and will be performed at mileage intervals. In those cases, there will likely be no symptoms. However, when a brake system makes a funny noise, causes vibration, is hard to use, will not slow the vehicle, prevents the vehicle from driving, makes the vehicle pull to one side, or leaks brake fluid, the vehicle will need a visit dedicated to the inspection of the brake system.

What are the initial diagnostic steps to take for a rough idle in a 2023 Mercedes-Benz GLE350?

When faced with a rough idle in your 2023 Mercedes-Benz GLE350, it's essential to adopt a methodical diagnostic approach to identify and resolve the issue effectively. Start by checking for error codes using an OBD-II scanner, as these codes can reveal specific problems within the engine's systems. Next, inspect the spark plugs for wear or fouling, as these components play a crucial role in engine performance. A dirty or clogged air filter should also be evaluated, since it can restrict airflow and contribute to an unstable idle. Additionally, examine the vacuum hoses for any signs of damage or leaks, which can disrupt the air-fuel mixture. Testing the mass airflow sensor is another critical step, as a malfunctioning sensor can significantly affect engine performance. Finally, don't overlook the fuel system; ensure that the fuel filter is clean and that the fuel injectors are functioning properly. By following these initial diagnostic steps, you can effectively narrow down the potential causes of a rough idle and take the necessary actions to restore your vehicle's performance.

What are the common problems that could cause a rough idle in a 2023 Mercedes-Benz GLE350?

When diagnosing a rough idle in a 2023 Mercedes-Benz GLE350, it's essential to consider several common problems that could be affecting your vehicle's performance. One of the primary culprits is a dirty or clogged air filter, which can significantly restrict airflow to the engine, leading to an uneven idle. Additionally, faulty spark plugs are notorious for causing misfires; if they are worn out, they can disrupt the combustion process, resulting in a rough idle. Another potential issue is vacuum leaks, which can disturb the air-fuel mixture necessary for optimal engine performance. Problems within the fuel system, such as a clogged fuel filter or a malfunctioning fuel pump, can also hinder fuel delivery, contributing to an unstable idle. Furthermore, a malfunctioning mass airflow sensor may provide incorrect readings of incoming air, adversely affecting the air-fuel mixture. Lastly, issues with the Exhaust Gas Recirculation (EGR) valve can lead to improper recirculation of exhaust gases, further impacting engine performance. By addressing these common problems through regular maintenance and timely repairs, you can help ensure a smoother idle and overall better performance of your GLE350.

How urgent is it to address the rough idle in my 2023 Mercedes-Benz GLE350?

Addressing a rough idle in your 2023 Mercedes-Benz GLE350 is not just a matter of comfort; it’s crucial for the overall health of your vehicle. Ignoring this symptom can lead to a cascade of issues, including decreased fuel efficiency and potential engine misfires, which may escalate into more severe engine damage over time. For DIY enthusiasts, it’s essential to recognize that a rough idle often indicates underlying problems within the engine, fuel system, or ignition system. By taking the initiative to diagnose and resolve these issues promptly, you can prevent costly repairs and ensure your vehicle runs smoothly. Regular maintenance checks and timely interventions can significantly enhance the longevity and reliability of your GLE350, making it imperative to address any signs of a rough idle as soon as they arise.

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2023 Mercedes-Benz GLE350 Rough Idle: Causes & Repairs