2017 Hyundai Elantra Has Rough Idle

Troubleshooting Causes of Rough Idle in Your 2017 Hyundai Elantra 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 2017 Hyundai Elantra 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 Hyundai Elantra 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 2017 Hyundai Elantra?

When addressing a rough idle in your 2017 Hyundai Elantra, it's essential to adopt a methodical diagnostic approach. Begin by checking the spark plugs, as they play a crucial role in engine performance; worn or fouled plugs can lead to uneven idling. Next, inspect the air filter to ensure it is clean and unobstructed, as a clogged filter can restrict airflow and negatively impact engine function. Following this, examine the fuel system, including the fuel filter and injectors, for any blockages that could hinder fuel delivery. Utilizing an OBD-II scanner to check for error codes can provide insights into underlying issues, guiding your next steps. Additionally, inspect the vacuum hoses for leaks, as any damage can disrupt the air-fuel mixture, contributing to rough idling. Finally, take a look at the throttle body for any carbon buildup or dirt that may affect its operation. By systematically addressing these areas, you can effectively diagnose and resolve the rough idle issue in your vehicle.

What are the common causes of a rough idle in a 2017 Hyundai Elantra?

When dealing with a rough idle in your 2017 Hyundai Elantra, it's crucial to understand the common problems that may 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 clogged fuel filters or injectors, 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 Exhaust Gas Recirculation (EGR) valve, as a faulty EGR can lead to similar symptoms. By identifying and addressing these common problems, you can take significant steps toward restoring your vehicle's smooth operation.

How urgent is it to address the rough idle in a 2017 Hyundai Elantra?

Addressing a rough idle in your 2017 Hyundai Elantra should be treated with urgency, as it can signal underlying issues that, if neglected, may lead to more significant problems down the line. A rough idle often indicates that the engine is not running smoothly, which can stem from minor issues like dirty fuel injectors or spark plugs that can be resolved through routine maintenance. However, it can also point to more serious concerns such as a malfunctioning sensor, vacuum leaks, or ignition system failures that could compromise your vehicle's performance and safety. Ignoring these symptoms can result in decreased fuel efficiency, poor engine performance, and potentially costly repairs. For DIY enthusiasts, it’s advisable to start with basic maintenance checks, such as inspecting and cleaning spark plugs and fuel injectors, before considering more complex diagnostics. Promptly addressing a rough idle not only enhances your vehicle's performance but also helps prevent further complications, ensuring a smoother and safer driving experience.

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