2017 Mercedes-Benz C43 AMG Has Rough Idle

Resolve Rough Idle in 2017 Mercedes-Benz C43 AMG for a Smoother Ride

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Reviewed by
Bo Fader
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 2017 Mercedes-Benz C43 AMG 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 2017 Mercedes-Benz C43 AMG 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.

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.

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 steps to diagnose a rough idle in a 2017 Mercedes-Benz C43 AMG?

To effectively diagnose a rough idle in your 2017 Mercedes-Benz C43 AMG, start with a systematic approach that prioritizes simpler checks before delving into more complex diagnostics. Begin by using a diagnostic scanner to check for any fault codes, as these can quickly highlight specific issues within the vehicle's computer system. Next, inspect the spark plugs for wear or fouling, since these components are crucial for proper ignition and can significantly impact engine performance. Following this, examine the ignition system, including coils and wires, to ensure they are functioning correctly, as any faults here can lead to misfires. It's also essential to check the air intake system; a clean air filter is vital for maintaining the correct air-fuel mixture, which is necessary for smooth idling. Additionally, inspect the fuel system components, such as injectors and the fuel pump, to confirm they are operating efficiently, as fuel delivery issues can contribute to rough idling. Lastly, verify the condition of vacuum hoses, as any leaks can disrupt engine performance. By following this structured diagnostic approach, you can effectively identify and address the root cause of the rough idle in your vehicle.

What are the common problems that could cause a rough idle in a 2017 Mercedes-Benz C43 AMG?

When diagnosing a rough idle in a 2017 Mercedes-Benz C43 AMG, it's crucial to identify several common issues that may be affecting your vehicle's performance. A dirty or malfunctioning mass airflow sensor can significantly disrupt the air-fuel mixture, leading to an unstable idle. Additionally, vacuum leaks can create an improper air-fuel ratio, further worsening the rough idle. Worn or faulty spark plugs are also frequent culprits, as they can cause engine misfires that manifest as rough idling. A clogged fuel filter may restrict fuel flow, impacting engine performance and contributing to the problem. Moreover, issues with fuel injectors can disrupt the delivery of fuel to the engine, while a malfunctioning oxygen sensor can negatively affect the air-fuel mixture, resulting in similar symptoms. By understanding these common problems, DIY enthusiasts can take proactive steps in troubleshooting and resolving the rough idle in their Mercedes-Benz C43 AMG, ensuring smoother operation and enhanced performance.

How urgent is it to address the rough idle in my 2017 Mercedes-Benz C43 AMG?

Addressing a rough idle in your 2017 Mercedes-Benz C43 AMG is not just a matter of comfort; it is crucial for the overall health of your vehicle. A rough idle can signal serious underlying problems, such as engine misfires or fuel delivery issues, which, if left unchecked, may escalate into more significant and costly repairs. Additionally, a rough idle often leads to decreased fuel efficiency, meaning you could be spending more at the pump while also risking further damage to your engine components. The urgency to resolve this issue cannot be overstated, as neglecting it may compromise your vehicle's performance and safety. By prioritizing timely maintenance and repairs, you not only enhance your driving experience but also safeguard your investment in the long run. Therefore, if you notice a rough idle, it is advisable to take action immediately to prevent further complications.

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