2021 Audi S4 Is Leaking Oil

Troubleshooting Oil Leaks in Your 2021 Audi S4: Common Causes and 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 2021 Audi S4 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 Audi S4 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 2021 Audi S4?

When diagnosing an oil leak in your 2021 Audi S4, it's essential to adopt a systematic approach that prioritizes simplicity before delving into more complex issues. Begin by locating the leak; check beneath your vehicle for any visible oil drips or pools, as this can provide immediate clues. Next, inspect the engine components, focusing on areas like the oil filter, oil pan, valve cover gasket, and oil drain plug, as these are common culprits for leaks. It's also crucial to check your oil level; a significant drop may indicate a leak that needs addressing. Pay special attention to the oil filter for any signs of damage or leakage, as a faulty filter can often be the source of the problem. Additionally, examine the oil pan for cracks or other damage that could lead to leaks. Look for oil stains or residue around gaskets and seals, which can help pinpoint the leak's origin. If these steps do not reveal the source of the leak or if you feel uncertain about your findings, consulting a professional mechanic with expertise in Audi vehicles is advisable for a thorough diagnosis and repair. By following this structured diagnostic approach, you can effectively identify and address the oil leak in your Audi S4.

What are the common causes of oil leaks in a 2021 Audi S4?

When dealing with oil leaks in a 2021 Audi S4, 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, leading to leaks. Additionally, valve cover gaskets are known to deteriorate, allowing oil to escape from the top of the engine. Another potential source of leaks is the oil filter housing gasket; if this component fails, it can result in oil seeping around the oil filter area. Furthermore, worn camshaft seals can also contribute to oil leaks, particularly from the camshaft region, while crankshaft seal degradation can lead to leaks near the crankshaft. Addressing these issues promptly is essential to prevent further engine damage and maintain the performance of your Audi S4. Regular inspections and maintenance can help you catch these problems early, ensuring your vehicle remains in optimal condition.

How urgent is it to address the oil leak in my 2021 Audi S4?

Addressing an oil leak in your 2021 Audi S4 is not just a matter of routine maintenance; it is an urgent issue that requires immediate attention. Oil leaks can significantly reduce oil levels, leading to inadequate lubrication of engine components, which can cause severe damage over time. Furthermore, neglecting an oil leak can result in engine overheating, potentially leading to costly repairs or even complete engine failure. The safety implications are equally concerning, as leaking oil can drip onto hot engine parts, creating a fire hazard. Therefore, it is crucial to act swiftly and address any signs of an oil leak to protect both your vehicle's performance and your safety on the road. Taking prompt action can save you from extensive repairs and ensure your Audi S4 remains in optimal condition.

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