2018 Mercedes-Benz CLA45 AMG Is Leaking Oil

Diagnosing Oil Leak Sources in Your 2018 Mercedes-Benz CLA45 AMG and Recommended Repair Solutions

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Reviewed by
Andrew Hajjar
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 Mercedes-Benz CLA45 AMG 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 Mercedes-Benz CLA45 AMG 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 steps should I take to diagnose the oil leak in my 2018 Mercedes-Benz CLA45 AMG?

To successfully diagnose an oil leak in your 2018 Mercedes-Benz CLA45 AMG, begin by locating the leak, which involves checking for visible oil spots under the vehicle. Once you have a general area, inspect the engine components, focusing on the oil filter, oil pan, valve cover gasket, and oil drain plug, as these are common culprits. It's also essential to check the oil level; a significant drop may indicate a leak. Pay particular attention to the oil filter to ensure it is securely installed and undamaged, as well as the oil pan for any signs of wear or leaks. The valve cover gasket should be examined for oil seepage, and the oil drain plug must be checked for tightness. If these steps do not reveal the source of the leak or if the problem appears to be more complex, it may be wise to consult a professional mechanic or a Mercedes-Benz service center for further assistance. This systematic approach not only helps in identifying the issue but also empowers you to take informed actions towards resolving the leak.

What are the common causes of oil leaks in a 2018 Mercedes-Benz CLA45 AMG?

When dealing with oil leaks in a 2018 Mercedes-Benz CLA45 AMG, it's crucial to understand the common culprits that may be at play. One frequent issue is the degradation of the oil pan gasket, which can wear out over time and lead to leaks. Additionally, the valve cover gasket is another area to inspect, as it can deteriorate and allow oil to escape from the top of the engine. The oil filter housing gasket is also a potential source of leaks; if it fails, oil may leak around the oil filter area. Furthermore, the oil cooler seal can degrade, resulting in leaks from this component. Lastly, don’t overlook the timing cover, as problems here can also contribute to oil leaks. By being aware of these common issues, DIY enthusiasts can take proactive steps to inspect and address oil leaks, ensuring their vehicle remains in optimal condition and preventing further engine damage. Regular maintenance and timely inspections are key to catching these problems early.

How urgent is it to address the oil leak in my 2018 Mercedes-Benz CLA45 AMG?

Addressing an oil leak in your 2018 Mercedes-Benz CLA45 AMG is crucial for maintaining both the performance and safety of your vehicle. The urgency of the situation largely hinges on the severity of the leak; even a minor leak can escalate into a major issue if left unattended. Insufficient oil levels can lead to increased friction within the engine, resulting in potential overheating and significant damage that could be costly to repair. Moreover, an oil leak poses safety risks, particularly if the oil comes into contact with hot engine components, which could ignite and lead to a fire hazard. While it may seem tempting to delay repairs, the long-term costs associated with neglecting an oil leak far outweigh the immediate expenses of addressing the issue. Therefore, it is advisable to act promptly to ensure your CLA45 AMG continues to operate smoothly and safely, preserving its performance and longevity.

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