2020 Hyundai Accent Has Rough Idle

Common Causes of Rough Idling in Your 2020 Hyundai Accent and How to Resolve Them

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Reviewed by
Andrew Hajjar
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 2020 Hyundai Accent 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 2020 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 2020 Hyundai Accent?

To effectively diagnose a rough idle in your 2020 Hyundai Accent, start with the simplest checks to identify potential issues. Begin by using an OBD-II scanner to check for any error codes, as these can provide immediate insights into underlying problems. Next, inspect the spark plugs for wear or fouling, as these components are crucial for proper engine performance. A dirty or clogged air filter should also be examined, since it can restrict airflow and negatively impact idle quality. After these initial checks, look for vacuum leaks in hoses and connections, as these can disrupt the air-fuel mixture. Additionally, assess the fuel system, including the fuel filter and injectors, to ensure they are functioning correctly. Cleaning the throttle body can also be beneficial, as carbon buildup may hinder its operation. Finally, check for any restrictions in the exhaust system that could affect engine performance. By following this structured approach, you can systematically identify and address the causes of a rough idle, restoring your vehicle's smooth operation.

What are the common problems that could cause a rough idle in a 2020 Hyundai Accent?

When addressing a rough idle in a 2020 Hyundai Accent, it's crucial to identify the common problems that may be causing this issue. A dirty or clogged air filter can significantly restrict airflow to the engine, leading to an improper air-fuel mixture that results in a rough idle. Additionally, worn or faulty spark plugs can cause incomplete combustion, further contributing to an uneven idle. Vacuum leaks are another frequent culprit, as they can disrupt the air-fuel ratio, exacerbating the rough idling condition. Issues within the fuel system, such as a clogged fuel filter or a malfunctioning fuel pump, can also impede fuel delivery, making the idle rougher. Furthermore, a malfunctioning mass airflow sensor can provide incorrect data to the engine control unit, affecting the air-fuel mixture and leading to instability in idling. Lastly, a dirty throttle body can restrict airflow, complicating the engine's ability to maintain a steady idle. Regular maintenance and prompt repairs addressing these common issues can enhance your vehicle's performance, but if the rough idle persists, seeking assistance from a qualified mechanic is advisable for a thorough diagnosis and resolution.

How urgent is it to address the rough idle in my 2020 Hyundai Accent?

Addressing a rough idle in your 2020 Hyundai Accent is not just a matter of comfort; it is crucial for the overall health of your vehicle. Ignoring this symptom can lead to more severe engine problems, decreased fuel efficiency, and even costly repairs down the line. A rough idle often indicates underlying issues, such as a malfunctioning sensor, fuel delivery problems, or ignition system failures, which can worsen if left unattended. Moreover, a rough idle can compromise your vehicle's performance and safety, making it essential to diagnose and resolve the issue promptly. By taking action now, you can prevent further complications, ensure your vehicle runs smoothly, and extend its lifespan, making it a wise decision for any DIY enthusiast.

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2020 Hyundai Accent Rough Idle: Causes & Repairs | RepairPal