2017 Ford Fiesta Has Rough Idle

Causes of Rough Idling in Your 2017 Ford Fiesta and How to Resolve the Issue for a Smoother Ride

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Reviewed by
Devin Cabugcal
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 Ford Fiesta 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 Ford Fiesta 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.

Customers with drum brake systems often specify they have lost braking power, or that the vehicle's brakes are making noise. This is because brake drums do not dissipate heat very well, so the heat from hard braking will cause stress fractures. These fractures make can make noise on the brake shoes as the drum revolves around the shoes. Lastly, the brake shoes may not be problematic, but may cause a grinding noise while stopping. This would indicate the shoes have no braking material left, and the brake shoes must be changed before the vehicle can be safely driven.

Learn more about brake shoe symptoms

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 Ford Fiesta?

When faced with a rough idle in your 2017 Ford Fiesta, it's essential to adopt a methodical diagnostic approach to identify and resolve the issue. 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 are crucial for proper combustion and can lead to misfires if compromised. Following this, evaluate the air filter; a clean filter is vital for optimal airflow, and a clogged one can significantly hinder engine performance. Additionally, examine the vacuum hoses for any signs of damage or disconnection, as leaks can disrupt the air-fuel mixture, exacerbating idle issues. Testing the mass airflow sensor is also critical, as a malfunctioning sensor can alter the air-fuel ratio, leading to rough idling. Finally, inspect the throttle body for carbon buildup or dirt, which can impede airflow and affect engine performance. By systematically addressing these areas, you can effectively diagnose and remedy the rough idle in your Ford Fiesta, ensuring a smoother driving experience.

What are the common causes of a rough idle in a 2017 Ford Fiesta?

When dealing with a rough idle in your 2017 Ford Fiesta, 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 its failure can disrupt the combustion process and lead to rough idling. By identifying and addressing these common problems, you can restore your Fiesta's performance and enjoy a smoother driving experience.

How urgent is it to address the rough idle in a 2017 Ford Fiesta?

Addressing a rough idle in your 2017 Ford Fiesta should be treated with urgency, as it can signal underlying engine problems that may escalate if left unattended. A rough idle not only affects the vehicle's performance but can also lead to decreased fuel efficiency and increased wear on engine components, potentially resulting in costly repairs down the line. While some causes, like dirty fuel injectors or worn spark plugs, may be minor and easily resolved through routine maintenance, others could indicate serious issues such as a malfunctioning sensor or ignition system failure. Ignoring these symptoms can compromise your vehicle's safety and reliability, making it crucial to diagnose and address the problem promptly. By taking action early, you can ensure your Fiesta runs smoothly and avoid more significant complications in the future.

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