2020 Hyundai Elantra GT Has Rough Idle

Diagnosing Causes of Rough Idle in Your 2020 Hyundai Elantra GT and How to Resolve Them

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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 2020 Hyundai Elantra GT 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 Elantra GT 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 2020 Hyundai Elantra GT?

When faced with a rough idle in your 2020 Hyundai Elantra GT, it's essential to adopt a methodical diagnostic approach to identify and resolve the issue effectively. Start by checking for fault codes using an OBD-II scanner, as these codes can reveal specific problems within the engine's systems. Next, inspect the spark plugs for wear or fouling, as these components play a crucial role in engine performance. A clean air filter is also vital; ensure it is free from dirt and debris, as a clogged filter can restrict airflow and contribute to rough idling. Additionally, examine the vacuum hoses for any signs of damage or disconnection, as leaks can disrupt the air-fuel mixture. Don't overlook the throttle body; a buildup of carbon or dirt can hinder its function, affecting idle quality. Lastly, conduct a thorough inspection for vacuum leaks in the intake system, as these can introduce excess air and lead to instability at idle. By following these steps, you can systematically diagnose and address the rough idle issue, ensuring your Elantra GT runs smoothly.

What are the common causes of a rough idle in a 2020 Hyundai Elantra GT?

When experiencing a rough idle in your 2020 Hyundai Elantra GT, it's crucial to consider several common problems that could be at play. One of the first areas to check is the air filter; a dirty or clogged filter can significantly restrict airflow to the engine, leading to an uneven idle. Additionally, inspect the spark plugs for signs of fouling or wear, as these components are vital for proper combustion and can cause misfires if they are not functioning correctly. The mass airflow sensor is another critical component that can affect the air-fuel mixture; if it malfunctions, it can disrupt the engine's performance. Fuel injectors should also be examined for clogs or leaks, as these issues can hinder fuel delivery and contribute to rough idling. Furthermore, be on the lookout for vacuum leaks in the intake system, which can introduce unwanted air and create instability in engine performance. Lastly, faulty ignition coils can lead to misfires, exacerbating the rough idle issue. By systematically checking these components, you can identify and address the root cause of the rough idle, ensuring your Elantra GT runs smoothly.

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

Addressing a rough idle in your 2020 Hyundai Elantra GT is not just a matter of comfort; it is crucial for the vehicle's overall performance and longevity. Ignoring this symptom can lead to a cascade of problems, including decreased fuel efficiency and potential engine damage. A rough idle often indicates underlying issues such as malfunctioning sensors, clogged fuel injectors, or ignition system failures, which can worsen over time if left unchecked. The longer you wait to address these symptoms, the more likely you are to incur costly repairs down the line. By taking prompt action, you not only safeguard your vehicle's health but also enhance your driving experience. Therefore, it is essential to prioritize resolving a rough idle to prevent further complications and ensure the smooth operation of your Hyundai Elantra GT.

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