2018 Mazda CX-9 Is Leaking Oil

Diagnosing Oil Leak Sources in Your 2018 Mazda CX-9 and Effective Repair Strategies

Find Repair Location
Reviewed by
Devin Cabugcal
Written by RepairPal Car Genius
Updated January 14, 2025
0%
80% chance it's the
Oil System Components
0%
20% chance it's the
Engine Gaskets
The most common reasons a 2018 Mazda CX-9 is leaking oil are oil system component failure and leaking engine gaskets.
  • Oil System Components: A worn or damaged oil pump or filter can lead to low oil pressure, resulting in inadequate lubrication and potential engine damage.
  • Engine Gaskets: A worn or damaged engine gasket can lead to oil or coolant leaks, resulting in engine overheating or loss of lubrication.
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 Mazda CX-9 is leaking oil?

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.

Oil pans don't wear out or break like other parts, they generally only need to be replaced because of external damage from an accident or an improperly tightened drain plug. The main symptom you will experience is an oil leak underneath the engine of your car. The oil that leaks from a damaged oil pan will range from dark brown to dark black. If the leak is large enough or occurs for long enough the oil level will be low enough to turn the oil pressure or low oil level warning light on.

A bad oil level sensor may cause a false reading of the engine oil level. The oil level warning light may illuminate even when the oil level (checked manually) is within an acceptable range. The warning light may also come on and off intermittently if the sensor is faulty. An error code may be sent to the PCM and a check engine light may come on the dashboard as well if the sensor is bad.

The engine oil pressure warning light will come on if the engine oil pressure is low, or if the oil pressure sensor is faulty. In either case, engine power may be reduced significantly. The check engine light may also illuminate, and an on-board diagnostic (OBD) trouble code will be stored in the vehicle's computer.

What are the initial steps to diagnose the oil leak in a 2018 Mazda CX-9?

When diagnosing an oil leak in your 2018 Mazda CX-9, it's essential to adopt a systematic diagnostic approach that prioritizes straightforward methods before delving into more complex solutions. Begin by locating the leak; check beneath the vehicle for any visible oil spots or puddles, as this can provide immediate clues about the leak's source. Next, inspect the engine compartment for oil splatters, particularly around critical areas such as the valve cover gasket, oil filter, and oil pan. It's also crucial to check the oil level in the engine; a lower-than-normal level may indicate a leak. Pay special attention to the oil filter, ensuring it is securely installed and free from damage, as a loose filter can often be the culprit. Additionally, examine gaskets and seals for signs of wear or leaks, focusing on the valve cover gasket and oil pan gasket. If the leak remains elusive, consider using UV dye in the engine oil, which can help you trace the leak's origin with a UV light. By following these steps, you can effectively diagnose the oil leak and take the necessary actions to address it.

What are the common causes of oil leaks in a 2018 Mazda CX-9?

When dealing with oil leaks in a 2018 Mazda CX-9, it's crucial to understand the common culprits that may be at play. One frequent issue is a degraded or damaged oil pan gasket, which can wear out over time and lead to leaks. Additionally, a faulty valve cover gasket can allow oil to escape from the top of the engine, creating a mess and potentially affecting performance. Another common source of leaks is a loose or damaged oil filter; ensuring that the filter is properly secured can prevent this problem. Furthermore, cracked or damaged oil cooler lines can also contribute to oil leaks, so inspecting these lines for any signs of wear is essential. Lastly, various seals and gaskets throughout the engine can deteriorate over time, leading to leaks. By regularly checking these components and addressing any issues promptly, DIY enthusiasts can maintain their vehicle's performance and prevent further damage.

How urgent is it to address the oil leak in my 2018 Mazda CX-9?

Addressing an oil leak in your 2018 Mazda CX-9 is crucial, and the urgency of the situation cannot be overstated. A minor leak may seem manageable, but even small amounts of oil loss can lead to serious engine performance issues over time. Insufficient lubrication due to a leak can increase friction among engine components, potentially resulting in costly repairs or even complete engine failure. Moreover, the safety risks associated with an oil leak are significant; oil dripping onto hot engine parts can ignite, posing a fire hazard. By addressing the leak promptly, you not only safeguard your vehicle's performance but also protect yourself and others on the road. While the initial repair may require some investment, the long-term savings from preventing extensive damage make it a wise decision for any DIY enthusiast. Therefore, if you notice any signs of an oil leak, it is advisable to take action immediately to ensure the safe and efficient operation of your Mazda CX-9.

You’ve got options with RepairPal

Whether you need a more accurate auto repair estimate or help finding a reputable shop in your area, we’ve got you covered.