2023 Ford Mustang Has Rough Idle

Troubleshooting Causes of Rough Idle in Your 2023 Ford Mustang 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 2023 Ford Mustang 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 2023 Ford Mustang 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 steps to diagnose a rough idle in a 2023 Ford Mustang?

To effectively diagnose a rough idle in your 2023 Ford Mustang, start with a methodical approach that emphasizes simplicity and efficiency. Begin by using an OBD-II scanner to check for any error codes, as these can quickly point you to underlying issues. Next, inspect the spark plugs for wear or fouling, as faulty plugs are a common culprit of misfires that lead to rough idling. Following this, examine the ignition system, including coils and wires, to ensure they are functioning properly. A clean air intake system is crucial, so check the air filter and intake for obstructions that could hinder airflow. Don’t overlook the fuel system; inspect the fuel injectors, filter, and pump to confirm they are delivering fuel effectively. Additionally, look for any vacuum leaks in the hoses, as these can disrupt the air-fuel mixture. Finally, test the mass airflow sensor to ensure it is accurately measuring air intake. By following this structured diagnostic approach, you can identify and address the root causes of a rough idle, ensuring your Mustang runs smoothly.

What are the common problems that could cause a rough idle in a 2023 Ford Mustang?

When diagnosing a rough idle in a 2023 Ford Mustang, it's crucial to identify several common problems that may be affecting engine performance. A dirty or clogged air filter can significantly restrict airflow, leading to an uneven idle. Additionally, worn or faulty spark plugs can cause misfires, disrupting the combustion process and resulting in a rough idle. Vacuum leaks are another potential issue, as they can alter the air-fuel mixture and negatively impact engine efficiency. Problems within the fuel system, such as clogged fuel filters or malfunctioning fuel injectors, can hinder proper fuel delivery, contributing to idle irregularities. Furthermore, a malfunctioning mass airflow sensor (MAF) can misread incoming air, throwing off the air-fuel mixture and causing rough idling. Lastly, issues with the idle air control valve (IAC) can lead to improper idle speed control, exacerbating the problem. By addressing these common issues through regular maintenance and timely repairs, Mustang owners can ensure smoother engine performance and a more enjoyable driving experience.

How urgent is it to address the rough idle in my 2023 Ford Mustang?

Addressing a rough idle in your 2023 Ford Mustang should be treated with a sense of urgency, as it can indicate serious underlying engine problems that, if left unresolved, may lead to significant damage and costly repairs. Symptoms such as engine misfires, decreased fuel efficiency, and potential harm to engine components can arise from issues like faulty spark plugs, fuel system malfunctions, or air intake problems. For DIY enthusiasts, it’s crucial to recognize that while you may be tempted to delay repairs, doing so can exacerbate the situation, leading to more extensive and expensive fixes down the line. Regular maintenance and prompt attention to these symptoms not only enhance your vehicle's performance but also ensure its longevity. Therefore, if you notice a rough idle, consider conducting a thorough inspection or consulting a professional mechanic to diagnose the issue before it escalates, safeguarding both your Mustang's health and your investment.

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