2016 Hyundai Accent Has Rough Idle

Common Causes of Rough Idling in Your 2016 Hyundai Accent 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 Hyundai Accent has rough idle are a vacuum leak, an issue with the spark plugs, or a problem with the ignition coil.
  • Spark Plugs: A worn or fouled spark plug can cause misfires, rough idling, and decreased fuel efficiency due to incomplete combustion.
  • 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 Hyundai Accent 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.

Customers with drum brake systems often specify they have lost braking power, or that the vehicle's brakes are making noise. This is because brake drums do not dissipate heat very well, so the heat from hard braking will cause stress fractures. These fractures make can make noise on the brake shoes as the drum revolves around the shoes. Lastly, the brake shoes may not be problematic, but may cause a grinding noise while stopping. This would indicate the shoes have no braking material left, and the brake shoes must be changed before the vehicle can be safely driven.

Learn more about brake shoe symptoms

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 2016 Hyundai Accent?

When diagnosing a rough idle in a 2016 Hyundai Accent, it's crucial to follow a structured diagnostic approach that prioritizes simpler checks before delving into more complex issues. Begin by utilizing an OBD2 scanner to retrieve any Diagnostic Trouble Codes (DTCs), as these codes can provide immediate insights into potential problems affecting engine performance. Next, inspect for vacuum leaks, which are a common culprit for rough idling; look for any damaged hoses or loose connections that may disrupt airflow. After addressing vacuum issues, examine the spark plugs for signs of wear or fouling, as these can significantly impact combustion efficiency. If the spark plugs are in good condition, proceed to test the ignition coil to ensure it is functioning properly, since a faulty coil can lead to misfires and rough idling. Additionally, inspect critical engine components such as timing, compression, and exhaust systems for any abnormalities that could contribute to the issue. Pay special attention to the Crankshaft Position Sensor, as its malfunction can also lead to idle problems. If you notice any unusual sounds while the engine is idling, remove the serpentine belt and manually check each pulley for sticking or shifting. Finally, conduct a voltage test with a Digital Volt-Ohm Meter (DVOM) to identify any underlying electrical issues that may be affecting engine performance. By systematically following these steps, you can effectively diagnose and resolve the rough idle issue in your Hyundai Accent.

What are the common causes of rough idle in a 2016 Hyundai Accent?

When experiencing a rough idle in your 2016 Hyundai Accent, it's essential to consider several common problems that could be at play. One of the primary culprits is a vacuum leak, which can disrupt the air-fuel mixture and lead to unstable engine performance. Additionally, worn or faulty spark plugs can cause misfiring, resulting in a rough idle as the engine struggles to maintain a consistent rhythm. Ignition coil issues may also contribute to this problem, as they are crucial for delivering the necessary spark to ignite the fuel mixture. If your vehicle is displaying a timing over advanced code, specifically code 0011, this could indicate a timing issue that may be affecting idle quality. Furthermore, engine defects, such as dirty air filters or low-quality components, can exacerbate rough idling. By understanding these common causes, DIYers can effectively diagnose and address the rough idle issue in their Hyundai Accent, ensuring smoother engine performance.

How urgent is it to address the rough idle in a 2016 Hyundai Accent?

Addressing a rough idle in your 2016 Hyundai Accent is crucial for maintaining the vehicle's performance and safety. A rough idle can signal various underlying problems, such as a vacuum leak or issues with spark plugs and ignition coils, which, if ignored, may lead to more severe complications like engine stalling or poor fuel efficiency. Additionally, persistent rough idling can indicate serious mechanical issues, including low cylinder compression or exhaust leaks, which could result in costly repairs if not dealt with promptly. Moreover, components like the crankshaft position sensor, when malfunctioning, can severely impact engine performance and lead to unexpected shutdowns. By addressing the rough idle early, you not only enhance your vehicle's efficiency but also prevent further damage, ensuring a smoother and safer driving experience. Therefore, it is essential to take action as soon as you notice this symptom to safeguard your vehicle's health and your safety on the road.

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