2016 Chevrolet Impala Has Rough Idle

Troubleshooting Causes of Rough Idle in Your 2016 Chevrolet Impala and How to Resolve Them

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Reviewed by
Devin Cabugcal
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 2016 Chevrolet Impala 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 2016 Chevrolet Impala 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 2016 Chevrolet Impala?

When faced with a rough idle in your 2016 Chevrolet Impala, it's essential to adopt a systematic diagnostic approach to identify the root cause effectively. Start by checking for fault codes using an OBD-II scanner, as these codes can reveal specific issues within the engine's computer system. Next, inspect the spark plugs for wear or fouling, as damaged plugs can lead to misfires that contribute to an unstable idle. Don’t overlook the air filter; a clogged filter can restrict airflow, so ensure it’s clean and replace it if necessary. Additionally, examine the vacuum hoses for any signs of cracks or disconnections, as leaks can disrupt the air-fuel mixture. It's also crucial to assess the fuel system, including the fuel pump, filter, and injectors, to ensure they are functioning correctly. Finally, consider cleaning the throttle body to remove any carbon buildup that may be affecting airflow. By following these steps in order, you can effectively diagnose and address the rough idle issue in your Impala, potentially saving time and money on repairs.

What are the common causes of a rough idle in a 2016 Chevrolet Impala?

When diagnosing a rough idle in a 2016 Chevrolet Impala, it's essential to consider several common problems that could be at play. One of the primary culprits is a dirty or clogged air filter, which can significantly restrict airflow to the engine, leading to performance issues. Additionally, faulty spark plugs are notorious for causing misfires, which can manifest as a rough idle. Another potential issue is vacuum leaks; these can disrupt the delicate balance of the air-fuel mixture, resulting in an unstable idle. Fuel system problems, such as a clogged fuel filter or a malfunctioning fuel pump, can also hinder engine performance and contribute to rough idling. Furthermore, a malfunctioning mass airflow sensor can throw off the air-fuel mixture, exacerbating the issue. Lastly, don't overlook the EGR (Exhaust Gas Recirculation) valve, as a faulty EGR can interfere with the combustion process, leading to rough idling. By addressing these common causes through regular maintenance and timely repairs, you can effectively resolve the rough idle issue and ensure your Impala runs smoothly.

How urgent is it to address the rough idle in my 2016 Chevrolet Impala?

Addressing a rough idle in your 2016 Chevrolet Impala should be treated with urgency, as it often signals underlying issues that could escalate if ignored. A rough idle can lead to decreased fuel efficiency and drivability problems, which not only affect your driving experience but can also result in costly repairs down the line. Moreover, neglecting this symptom may cause further damage to critical engine components, potentially compromising your vehicle's safety and reliability. For DIY enthusiasts, it’s essential to recognize that timely maintenance and repairs can prevent more serious complications, ensuring your Impala runs smoothly and efficiently. By taking proactive steps to diagnose and resolve the rough idle, you can save yourself from more significant headaches and expenses in the future.

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