2011 Mercedes-Benz S600 Has Rough Idle

Resolve Rough Idle in 2011 Mercedes-Benz S600 for a Smoother Ride

Find Repair Location
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 2011 Mercedes-Benz S600 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 2011 Mercedes-Benz S600 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 initial diagnostic steps to take for a rough idle in a 2011 Mercedes-Benz S600?

When faced with a rough idle in your 2011 Mercedes-Benz S600, it's essential to adopt a systematic diagnostic approach to identify the root cause effectively. Start by checking for fault codes using a diagnostic scanner, as these codes can reveal specific issues within the vehicle's computer system. Next, inspect the spark plugs for wear or fouling, as these components play a crucial role in engine performance. A clean and unobstructed air filter is also vital; ensure it is free from debris to maintain proper airflow. Additionally, examine the vacuum lines for any signs of leaks, as these can disrupt the air-fuel mixture and lead to idle problems. The Mass Airflow Sensor (MAF) should be checked as well, since a malfunctioning MAF can significantly affect engine performance. Lastly, don't overlook the throttle body; cleaning it of any carbon buildup can improve idle quality. By following these steps, you can effectively diagnose and address the rough idle issue, ensuring your vehicle runs smoothly.

What are the common causes of a rough idle in a 2011 Mercedes-Benz S600?

When dealing with a rough idle in a 2011 Mercedes-Benz S600, it's essential to consider several common problems that could be at play. One of the primary culprits is a dirty or faulty mass airflow sensor, which can significantly disrupt the air-fuel mixture necessary for smooth engine operation. Additionally, vacuum leaks can create an imbalance in the air-to-fuel ratio, leading to an unstable idle. Worn-out spark plugs or malfunctioning ignition coils are also frequent offenders, as they can cause misfires that result in a rough engine idle. Another potential issue is a clogged fuel filter, which restricts fuel flow and can adversely affect engine performance. Lastly, problems with the idle air control valve can interfere with the engine's idle speed, contributing to the roughness. By systematically checking these components, DIYers can effectively diagnose and address the rough idle issue, ensuring their S600 runs smoothly once again.

How urgent is it to address the rough idle in my 2011 Mercedes-Benz S600?

Addressing a rough idle in your 2011 Mercedes-Benz S600 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 on gas while your vehicle's performance suffers. Ignoring these symptoms can also result in further damage to the engine, potentially compromising its longevity and reliability. Therefore, it is essential to prioritize this issue and take immediate action to diagnose and resolve the rough idle, ensuring your vehicle remains safe and efficient on the road.

You’ve got options with RepairPal

Whether you need a more accurate auto repair estimate or help finding a reputable shop in your area, we’ve got you covered.

2011 Mercedes-Benz S600 Rough Idle: Causes & Repairs