Mitsubishi Outlander PHEV Has Rough Idle

Diagnosing Causes of Rough Idle in Your Mitsubishi Outlander PHEV and Solutions for a Smoother Ride

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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 Mitsubishi Outlander PHEV 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 Mitsubishi Outlander PHEV 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.

Troubleshooting Rough Idle in a Mitsubishi Outlander PHEV

When troubleshooting a rough idle in your Mitsubishi Outlander PHEV, it's essential to adopt a methodical diagnostic approach. Begin by inspecting for vacuum leaks, as these can often be the simplest and most common culprits behind idle issues. Carefully examine hoses and connections for any signs of wear or disconnection. Next, turn your attention to the spark plugs; check for any signs of damage or excessive wear, as faulty spark plugs can significantly affect engine performance. If these initial checks do not resolve the issue, consider the ignition coils, which are critical for proper engine function. A failing ignition coil can lead to a range of symptoms, including a check engine light, poor performance, and increased emissions. If you notice any of these signs, it may be time to replace the ignition coils. By following this step-by-step diagnostic approach, you can effectively identify and address the root cause of the rough idle, ensuring your vehicle runs smoothly and efficiently.

What Could Cause a Rough Idle in a Mitsubishi Outlander PHEV?

A rough idle in your Mitsubishi Outlander PHEV can stem from several common issues that are often manageable with some DIY troubleshooting. One of the primary culprits is a vacuum leak, which can disrupt the air-fuel mixture and lead to an unstable idle. Additionally, worn or fouled spark plugs can hinder proper ignition, resulting in a rough engine performance. It's also essential to check the ignition coil, as any malfunction here can directly affect the engine's ability to maintain a smooth idle. Irregularities in air intake, such as blocked or damaged vacuum lines, can further exacerbate the problem. Moreover, a rich air-fuel mixture can not only cause rough idling but may also lead to poor throttle response and unusual exhaust emissions. Lastly, battery issues, particularly those related to charging or prolonged inactivity, can impact the overall performance of the vehicle, including idle quality. By systematically examining these areas, you can identify and address the root cause of the rough idle, ensuring your Outlander PHEV runs smoothly.

Why is My Mitsubishi Outlander PHEV Idling Rough and What Should I Do?

When your Mitsubishi Outlander PHEV is idling rough, it’s crucial to understand that neglecting this symptom can lead to more severe problems down the line. Issues such as vacuum leaks, worn spark plugs, or malfunctioning motor mounts not only affect your vehicle's performance but can also pose safety risks if left unaddressed. For instance, a rough idle may indicate that your engine is not running efficiently, which can lead to increased fuel consumption and potential engine damage. Additionally, if the check engine light is illuminated, it’s essential to diagnose the OBD II codes promptly, as they can provide insights into underlying issues that could escalate if ignored. By taking immediate action to inspect and repair these components, you not only enhance your vehicle's performance but also ensure a safer driving experience. Therefore, don’t delay in troubleshooting the causes of rough idling; addressing these concerns early can save you from costly repairs and keep your Mitsubishi Outlander PHEV running smoothly.

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Mitsubishi Outlander PHEV Rough Idle Causes & Repairs