2003 Mitsubishi Eclipse Has A Vacuum Leak

Diagnosing Vacuum Leaks in Your 2003 Mitsubishi Eclipse: Symptoms, Causes, and Repair Solutions

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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 2003 Mitsubishi Eclipse 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 2003 Mitsubishi Eclipse 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 2003 Mitsubishi Eclipse?

To effectively diagnose a vacuum leak in a 2003 Mitsubishi Eclipse, start with a thorough visual inspection of the vacuum hoses and connections. Look for any signs of wear, such as cracks or loose fittings, which can often be the source of leaks. Next, listen for any hissing sounds while the engine is running, as these can indicate escaping air. If the initial checks do not reveal the issue, utilize a vacuum gauge connected to the intake manifold to assess the vacuum levels at idle and during acceleration; abnormal readings can signal a leak. For a more hands-on approach, perform a spray test using carburetor cleaner or propane around suspected areas; a change in engine RPM will confirm a leak. If these methods are inconclusive, consider conducting a smoke test, which visually highlights leaks by introducing smoke into the intake system. Should these techniques fail to identify the problem, professional diagnostic tools like a smoke machine can provide a more accurate assessment. By following this structured approach, you can systematically identify and address vacuum leaks in your vehicle.

What are the common problems that could cause a vacuum leak in a 2003 Mitsubishi Eclipse?

When troubleshooting a vacuum leak in a 2003 Mitsubishi Eclipse, it's essential to understand the common problems that may be at play. One of the primary culprits is damaged vacuum hoses, which can deteriorate over time, leading to cracks or disconnections that allow air to escape. Additionally, a faulty intake manifold gasket can create gaps that disrupt the vacuum seal, resulting in performance issues. Another potential issue is a malfunctioning Positive Crankcase Ventilation (PCV) valve; if this component is clogged or defective, it can also contribute to a vacuum leak. Furthermore, a loose or damaged throttle body can compromise the vacuum system, affecting engine efficiency. Lastly, a broken vacuum brake booster may lead to significant leaks, impacting both braking performance and engine operation. By identifying these common problems, DIY enthusiasts can effectively diagnose and address vacuum leaks, ensuring their Mitsubishi Eclipse runs smoothly.

How urgent is it to repair a vacuum leak in a 2003 Mitsubishi Eclipse?

Repairing a vacuum leak in a 2003 Mitsubishi Eclipse is an urgent matter that should not be overlooked. A vacuum leak can significantly impact your vehicle's performance, leading to symptoms such as rough idling, stalling, and decreased power, which can make driving unsafe. Additionally, a compromised vacuum system can result in poor fuel economy, costing you more at the pump. If left unaddressed, a vacuum leak can cause further damage to other engine components, leading to more extensive and costly repairs down the line. Therefore, it is crucial to diagnose and repair any vacuum leaks as soon as they are detected to ensure the longevity and efficiency of your vehicle. Taking prompt action not only enhances your driving experience but also safeguards your investment in the car.

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2003 Mitsubishi Eclipse Vacuum Leak Causes & Repairs