2017 Audi S7 Has Rough Idle

Diagnosing the Causes of Rough Idle in Your 2017 Audi S7 and How to Restore Smooth Performance

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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 Audi S7 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 Audi S7 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 Audi S7?

To effectively diagnose a rough idle in your 2017 Audi S7, start with a systematic approach that prioritizes simpler checks before delving into more complex issues. Begin by using an OBD-II scanner to identify any fault codes that may indicate specific problems within the engine. Once you have this information, inspect the spark plugs for wear or damage, as faulty plugs can significantly affect engine performance. Next, examine the air filter for clogs, which can restrict airflow and contribute to a rough idle. It's also crucial to check the vacuum hoses for leaks or cracks, as these can disrupt the air-fuel mixture. After addressing these initial checks, assess the fuel system components, including the fuel pump and injectors, to ensure they are functioning correctly. Cleaning the throttle body can also help improve airflow, while testing the Mass Airflow Sensor (MAF) will confirm its proper operation. Finally, if the issue persists, consider checking the engine compression to ensure all cylinders are working efficiently. By following this structured diagnostic approach, you can effectively identify and resolve the causes of a rough idle in your Audi S7.

What are the common problems that could cause a rough idle in a 2017 Audi S7?

When diagnosing a rough idle in your 2017 Audi S7, it's essential to consider several common issues that could be at play. One of the primary culprits is a dirty or faulty mass airflow sensor, which can disrupt the delicate balance of air and fuel entering the engine, leading to an uneven idle. Additionally, vacuum leaks can create an improper air-fuel ratio, further exacerbating the roughness of the idle. It's also crucial to inspect the spark plugs; worn or malfunctioning plugs can cause misfires, resulting in a noticeable rough idle. Another potential issue is a clogged fuel filter, which can restrict fuel flow and negatively impact engine performance. Lastly, don't overlook the oxygen sensors, as their failure can significantly affect the air-fuel mixture, contributing to the rough idle. By addressing these common problems through regular maintenance and timely repairs, you can restore smooth operation to your Audi S7's engine.

How urgent is it to address the rough idle in my 2017 Audi S7?

Addressing a rough idle in your 2017 Audi S7 is not just a matter of comfort; it is crucial for the overall health of your vehicle. A rough idle can indicate serious underlying issues such as faulty spark plugs, a clogged fuel filter, or a malfunctioning oxygen sensor. If left unchecked, these problems can lead to decreased fuel efficiency, engine misfires, and even significant damage to engine components, which can be costly to repair. Therefore, it is essential to act promptly. Regular maintenance and timely repairs can prevent these issues from escalating, ensuring that your Audi S7 continues to perform optimally. For those inclined to take a DIY approach, consider starting with a thorough inspection of the spark plugs and fuel system, as these are common culprits. However, if the problem persists, seeking the expertise of a qualified mechanic is advisable to accurately diagnose and resolve the issue before it leads to more severe consequences.

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2017 Audi S7 Rough Idle: Causes & Repair Costs | RepairPal