2017 Kia Forte5 Has Rough Idle

Diagnosing Causes of Rough Idle in Your 2017 Kia Forte5 and Solutions for a Smoother Ride

Find Repair Location
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 2017 Kia Forte5 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 Kia Forte5 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 steps to diagnose the rough idle issue in a 2017 Kia Forte5?

To effectively diagnose a rough idle issue in your 2017 Kia Forte5, start with a systematic approach that prioritizes simpler checks before delving into more complex diagnostics. Begin by using an OBD-II scanner to check for any fault codes, as these can quickly point you to underlying problems. Next, inspect the spark plugs for wear or fouling, as faulty plugs are a common culprit of rough idling. Following this, examine the air filter; a clogged filter can restrict airflow and exacerbate idle issues. It's also crucial to check for vacuum leaks, as these can disrupt the air-fuel mixture, leading to performance problems. After addressing these initial checks, turn your attention to the fuel system, ensuring that the fuel filter and injectors are functioning properly. Additionally, inspect the throttle body for any buildup that could hinder its operation. Finally, use diagnostic tools to check for engine misfires, as these can significantly impact idle quality. By following this structured diagnostic approach, you can effectively identify and resolve the rough idle issue, restoring your vehicle's performance.

What are the common causes of a rough idle in a 2017 Kia Forte5?

When dealing with a rough idle in your 2017 Kia Forte5, it's crucial to understand the common problems that could be at play. One of the first areas to check is the air filter; a dirty or clogged air filter can significantly restrict airflow to the engine, leading to performance issues. Additionally, inspect the spark plugs, as worn or faulty plugs can cause misfiring, which directly contributes to a rough idle. Another potential culprit is vacuum leaks, which can disrupt the air-fuel mixture and result in unstable idling. Don't overlook the fuel system; issues such as a clogged fuel filter or malfunctioning fuel injectors can severely impact engine performance. Furthermore, the mass airflow sensor plays a vital role in regulating the air-fuel mixture, and if it's faulty, it can lead to rough idling as well. Lastly, consider the EGR valve; if it's not functioning correctly, it can disrupt the combustion process, causing the engine to idle unevenly. By systematically checking these components, you can identify and address the root cause of the rough idle, ensuring your Kia Forte5 runs smoothly.

How urgent is it to address the rough idle in my 2017 Kia Forte5?

Addressing a rough idle in your 2017 Kia Forte5 is crucial for maintaining the vehicle's performance and longevity. A rough idle can indicate underlying issues such as problems with the fuel system, ignition components, or engine sensors, which, if left unresolved, may lead to more severe complications. Ignoring this symptom can result in decreased fuel efficiency and diminished engine performance, ultimately causing damage to other critical components. Moreover, a rough idle may signal serious problems that could escalate if not promptly addressed, potentially leading to costly repairs. Therefore, it is essential to prioritize this issue and conduct regular maintenance checks to ensure your vehicle operates smoothly and efficiently, safeguarding against future complications and ensuring a safer driving experience.

You’ve got options with RepairPal

Whether you need a more accurate auto repair estimate or help finding a reputable shop in your area, we’ve got you covered.

2017 Kia Forte5 Rough Idle Causes & Repair Costs | RepairPal