2018 Mitsubishi Outlander Sport Has A Vacuum Leak

Diagnosing Vacuum Leaks in Your 2018 Mitsubishi Outlander Sport and Effective Repair Strategies

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Reviewed by
Devin Cabugcal
Written by RepairPal Car Genius
Updated January 14, 2025
0%
40% chance it's the
Leaking Vacuum Hoses
0%
30% chance it's the
Leaking Gaskets and Seals
0%
20% chance it's the
Bad Actuators and Valves
0%
10% chance it's
Something else
The most common reasons a 2018 Mitsubishi Outlander Sport has a vacuum leak are leaking vacuum hoses, leaking gaskets and seals, or bad actuators and valves.
  • Leaking Vacuum Hoses: A cracked or disconnected vacuum hose can lead to a loss of engine vacuum, resulting in poor engine performance and increased fuel consumption.
  • Leaking Gaskets and Seals: Aged or damaged gaskets and seals can lead to fluid leaks, resulting in loss of engine oil or coolant and potential engine damage.
  • Bad Actuators and Valves: A malfunctioning actuator or valve can disrupt the proper operation of the vehicle's systems, leading to issues such as poor engine performance or erratic behavior of components like the HVAC system.
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 Mitsubishi Outlander Sport has a vacuum leak?

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.

Problems with the intake manifold gasket can create the following symptoms:

  • Illuminated check engine light
  • Erratic engine performance
  • Oil and coolant leaks
  • Poor gas mileage
  • Stalling

» LEARN MORE: Intake manifold gasket symptoms

Rough idling, lack of power, engine oil leaks, engine burning oil, and illumination of the check engine light are all possible if the PCV valve has clogged. If the check engine light comes on, the on-board diagnostics (OBD) trouble codes will most likely relate to manifold vacuum, air and fuel mixture, PCV system, mass airflow sensor readings, and exhaust and emissions readings. These are all affected in the event the PCV valve is clogged, is stuck fully open, or is stuck fully closed, however, if the valve is stuck fully open, the engine oil seals are not in danger of overpressure.

A bad valve cover gasket will result in an oil leak. You may notice oil under the car or on other parts under the hood. You might also notice a burning smell while driving.

» LEARN MORE: Signs of a bad valve cover gasket

Any time there is an emissions fault the check engine light will be displayed. The purpose of the check engine light is to inform the driver that an emission related fault has been found, and that there are on-board diagnostic (OBD) trouble codes stored in the powertrain or engine control module. Additionally, since the emissions systems are so intertwined into engine control and transmission control systems, symptoms may include nearly any sort of drivability concerns. This may include harsh shifting, failure to shift, hesitation on acceleration, jerking, engine failure to start or run, loss of power, or any number of other drivability issues.

What are the steps to diagnose a vacuum leak in a 2018 Mitsubishi Outlander Sport?

To effectively diagnose a vacuum leak in a 2018 Mitsubishi Outlander Sport, start with a thorough visual inspection of the engine bay. Look for any damaged or disconnected vacuum hoses, paying close attention to cracks, holes, or loose connections that could compromise the system. Next, listen for any hissing noises while the engine is running, as these sounds can help you identify the location of a potential leak. If the issue remains elusive, consider using a vacuum gauge to measure the vacuum levels at idle and during engine revs; a reading lower than normal can indicate a leak. For a more hands-on approach, perform a spray test by applying carburetor cleaner or propane around the vacuum hoses and intake manifold. If the engine's RPM changes, it suggests that air is being drawn in through a leak. If these methods do not yield results, a smoke test can be employed, where smoke is introduced into the intake system to visually reveal any escaping smoke from leaks. Should these DIY methods fail, it may be necessary to consult a professional mechanic who can utilize advanced diagnostic tools to accurately pinpoint the issue. By following this structured approach, you can systematically identify and address vacuum leaks in your vehicle.

What are the common causes and symptoms of a vacuum leak in a 2018 Mitsubishi Outlander Sport?

When tackling a vacuum leak in your 2018 Mitsubishi Outlander Sport, it's essential to recognize the common problems that can arise. One of the primary culprits is worn-out hoses, which can crack or develop holes over time, allowing air to escape and disrupting the engine's performance. Additionally, a faulty intake manifold gasket can lead to significant leaks, as can loose connections between vacuum hoses and fittings. If you notice a hissing noise emanating from the engine bay, it may indicate a leak, particularly if the brake pedal feels unusually hard to press, suggesting a problem with the vacuum brake booster. Symptoms such as rough idling, decreased engine performance, and the illumination of the check engine light are all signs that a vacuum leak may be present. By understanding these common causes and symptoms, you can take the necessary steps to diagnose and potentially fix the issue, ensuring your vehicle runs smoothly and efficiently.

How urgent is it to repair a vacuum leak in a 2018 Mitsubishi Outlander Sport?

Addressing a vacuum leak in your 2018 Mitsubishi Outlander Sport is crucial for maintaining optimal engine performance and ensuring safety on the road. A vacuum leak can lead to rough idling, stalling, and misfiring, which not only affects your driving experience but also decreases fuel efficiency. If left unattended, the leak can cause further damage to engine components, resulting in more expensive repairs down the line. Additionally, a vacuum leak can interfere with your vehicle's emissions control systems, potentially leading to failed emissions tests and increased pollution. Most importantly, severe leaks can compromise critical systems like braking, posing significant safety risks. Therefore, it is essential to address any signs of a vacuum leak promptly to protect your vehicle's performance, prevent costly repairs, and ensure your safety while driving.

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2018 Mitsubishi Outlander Sport Vacuum Leak | RepairPal