2021 Mercedes-Benz GLS450 Is Leaking Oil

Common Causes of Oil Leaks in Your 2021 Mercedes-Benz GLS450 and How to Address Them

Find Repair Location
Reviewed by
Bo Fader
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 2021 Mercedes-Benz GLS450 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 2021 Mercedes-Benz GLS450 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.

An oil leak may be noted on the ground where the vehicle is parked. However, many vehicles have plastic trays underneath the engine that may catch leaking oil and conceal the leak. In such cases, a low oil level, a burning oil smell, or even smoke from oil burning in the engine bay may be noted.

»MORE: Signs of a bad oil pan gasket

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 diagnostic steps to identify the source of the oil leak in a 2021 Mercedes-Benz GLS450?

When tackling an oil leak in your 2021 Mercedes-Benz GLS450, start with a thorough visual inspection of both the engine and undercarriage. Look for any obvious signs of oil, such as puddles or stains, which can help pinpoint the leak's location. Next, check the oil levels to assess if there has been a significant loss, indicating a potential leak. Pay close attention to the oil filter and drain plug, as these components can often be the culprits if they are loose or damaged. Additionally, inspect the gaskets and seals around the engine, including the valve cover and oil pan gaskets, for any signs of wear or deterioration. If the leak remains elusive, consider performing a pressure test on the oil system to uncover hidden leaks. For a more advanced approach, adding UV dye to the engine oil can help you trace the leak's source when illuminated with a UV light. If these steps do not yield results, consulting a qualified mechanic may be necessary for a comprehensive diagnosis and repair. By following these diagnostic steps, you can effectively identify and address the oil leak in your vehicle.

What are the common causes of oil leaks in a 2021 Mercedes-Benz GLS450?

When dealing with oil leaks in a 2021 Mercedes-Benz GLS450, it's essential to understand the common culprits that may be at play. One frequent issue is a degraded or damaged oil pan gasket, which can deteriorate over time and lead to leaks. Additionally, worn-out valve cover gaskets can allow oil to escape from the top of the engine, creating noticeable drips. Another area to inspect is the oil filter housing gasket; if this component is faulty, it can result in oil leaking around the oil filter. Furthermore, leaking oil cooler lines can contribute to oil loss, so checking these lines for signs of wear is crucial. Lastly, damaged oil seals, including the crankshaft and camshaft seals, can also be a source of leaks. Addressing these problems promptly is vital to prevent further engine damage and maintain the performance of your GLS450. By being aware of these common issues, DIY enthusiasts can take proactive steps to diagnose and resolve oil leaks effectively.

How urgent is it to address the oil leak in a 2021 Mercedes-Benz GLS450?

Addressing an oil leak in your 2021 Mercedes-Benz GLS450 is not just a matter of routine maintenance; it is a critical issue that demands immediate attention. Oil is vital for lubricating engine components, and a leak can lead to a dangerous loss of oil, resulting in inadequate lubrication and potential engine damage. Moreover, the presence of leaking oil poses a serious fire hazard, especially if it comes into contact with hot engine parts. Continuing to drive with an oil leak can exacerbate the problem, leading to more extensive and costly repairs down the line. By promptly addressing the oil leak, you not only safeguard the performance and longevity of your vehicle but also ensure your safety on the road. Ignoring this issue could lead to severe consequences, making it imperative to take action as soon as possible.

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.