2022 Subaru Forester Has Rough Idle

Troubleshooting Causes of Rough Idle in Your 2022 Subaru Forester and How to Resolve Them

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Reviewed by
Aisha
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 2022 Subaru Forester 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 2022 Subaru Forester 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.

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 2022 Subaru Forester?

When faced with a rough idle in your 2022 Subaru Forester, start your diagnostic journey by checking for fault codes using an OBD-II scanner. This tool can reveal any underlying issues that may be affecting engine performance. Next, inspect the spark plugs; they should be clean and functioning properly, as worn or fouled plugs can significantly impact idle quality. Don’t overlook the air filter; a clogged filter can restrict airflow, leading to an uneven idle. Additionally, examine the vacuum hoses for any leaks, as these can disrupt the air-fuel mixture essential for smooth engine operation. A thorough inspection of the throttle body is also crucial; any carbon buildup can hinder its performance. Finally, ensure that your fuel system, including the pump, filter, and injectors, is operating correctly, as fuel delivery issues can contribute to a rough idle. By systematically addressing these areas, you can effectively diagnose and potentially resolve the rough idle issue in your Subaru Forester.

What are the common problems that could cause a rough idle in a 2022 Subaru Forester?

When dealing with a rough idle in your 2022 Subaru Forester, it's essential to consider several common problems that could be affecting your vehicle's performance. 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 an uneven idle. Additionally, inspect the spark plugs, as worn or faulty plugs can cause misfiring, which is a frequent culprit behind rough idling. Another critical aspect to examine is the vacuum system for any leaks, as these can disrupt the air-fuel mixture and result in an unstable idle. Fuel system issues, such as a clogged fuel filter or a malfunctioning fuel pump, can also impact engine performance, contributing to rough idling. Furthermore, the Mass Airflow Sensor (MAF) plays a vital role in regulating the engine's air intake; if it's malfunctioning, it can cause the engine to run either too rich or too lean, leading to idle problems. Lastly, the Idle Air Control Valve (IACV) should be checked, as a dirty or faulty IACV may fail to maintain the correct idle speed. By addressing these common issues through regular maintenance and timely repairs, you can help ensure that your Subaru Forester runs smoothly and efficiently.

How urgent is it to address the rough idle in a 2022 Subaru Forester?

Addressing a rough idle in your 2022 Subaru Forester should be treated with a sense of urgency, as it can indicate underlying issues that, if left unresolved, may lead to more significant problems. Symptoms such as a rough idle can stem from various sources, including faulty spark plugs, a clogged fuel filter, or ignition system malfunctions. Ignoring these signs not only risks decreased fuel efficiency and engine misfires but can also result in costly damage to engine components over time. For DIY enthusiasts, tackling this issue promptly can save you from more extensive repairs down the line. Regular maintenance and timely interventions are key to ensuring your vehicle operates smoothly and efficiently. Therefore, while it may not be an immediate emergency, addressing a rough idle should be a priority to maintain your Subaru's performance and longevity.

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Troubleshooting Rough Idle in 2022 Subaru Forester