2018 Dodge Challenger Has Rough Idle

Troubleshooting Causes of Rough Idle in Your 2018 Dodge Challenger 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 2018 Dodge Challenger 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 2018 Dodge Challenger 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.

Brake caliper failure occurs in two different ways, and they create different symptoms.

The caliper can become stuck, in which case it won't release the brake pads. The seized caliper will cause the vehicle to brake constantly on one side, forcing the car to move toward that side. This pulling will be accompanied by a strong odor from one wheel.

Another way calipers fail is by leaking. If the caliper leaks, the brake pedal will feel too easy to push, and will sink all the way to the floor when held. Braking will become less effective the longer this goes on. There may also be brake fluid leaking onto the wheel.

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.

Brake rotors are mainly maintenance free, but when they have been subjected to abnormally hard use, the heat they absorb can cause the metal to turn blue, and cracking to occur. When this occurs, customers often specify they have lost braking power, or the vehicle's brakes are making noise. There may be no symptoms at all related to changing the brake rotors, since it is recommended to change brake rotors on most modern vehicles when performing a standard brake service.

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 2018 Dodge Challenger?

When faced with a rough idle in your 2018 Dodge Challenger, 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 air filter; a dirty or clogged filter can significantly hinder airflow, leading to performance issues. Following this, examine the spark plugs for wear or fouling, as these components are crucial for proper ignition and can cause misfires if compromised. Additionally, take a close look at the fuel system, including the fuel filter and injectors, to ensure they are functioning correctly and not contributing to the rough idle. Don't overlook the throttle body, as a buildup of dirt can disrupt the air-fuel mixture, exacerbating the problem. Lastly, check the PCV valve, as a malfunctioning valve can also lead to irregular idling. By systematically addressing these areas, you can effectively diagnose and remedy the rough idle in your Challenger, ensuring a smoother driving experience.

What are the common problems that could cause a rough idle in a 2018 Dodge Challenger?

When diagnosing a rough idle in your 2018 Dodge Challenger, it's essential to consider several common issues that could be affecting your vehicle's performance. One of the primary culprits is a dirty or clogged air filter, which can significantly restrict airflow to the engine, leading to an uneven idle. Additionally, worn or faulty spark plugs may cause misfiring, further contributing to the roughness you experience. It's also crucial to check for vacuum leaks, as these can disrupt the air-fuel mixture, resulting in instability during idling. Fuel system problems, such as a clogged fuel filter or a malfunctioning fuel pump, can also impact engine performance and lead to a rough idle. Furthermore, a faulty oxygen sensor can alter the air-fuel ratio, exacerbating the issue. Lastly, inspect the throttle body for carbon buildup or sensor malfunctions, as these can disrupt airflow and contribute to a rough idle. By addressing these common problems through regular maintenance and timely repairs, you can enhance your Challenger's performance and enjoy a smoother driving experience.

How urgent is it to address the rough idle in a 2018 Dodge Challenger?

Addressing a rough idle in your 2018 Dodge Challenger should be treated as a priority due to the potential risks and complications that can arise from neglecting this symptom. A rough idle often indicates underlying engine issues, such as dirty fuel injectors or faulty spark plugs, which, if left unresolved, can escalate into more severe problems, including engine damage and decreased performance. Ignoring these signs not only compromises your vehicle's fuel efficiency but can also lead to costly repairs down the line. Moreover, a rough idle can affect the overall driving experience, making it less enjoyable and potentially unsafe. Therefore, it is crucial to diagnose and rectify the cause of the rough idle promptly to ensure the longevity and reliability of your Challenger, ultimately safeguarding your investment and enhancing your driving experience.

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2018 Dodge Challenger Rough Idle: Causes & Repairs