Excessive Oil Consumption on my 2016 Audi S5 Coupe

ClearTheCode admin answer:

Excessive oil consumption on the 3.0T supercharged engine in your 2016 Audi S5 Coupe, while sometimes considered 'normal' by Audi up to a certain threshold (often 1 quart per 1,200 miles), warrants investigation, especially if it's a recent development or increasing. Given no visible leaks or smoke, the oil is likely being consumed internally.

1. Monitor and Document: Start by meticulously documenting your oil consumption. Note the date, mileage, and amount of oil added each time. This data will be crucial for diagnosis and any potential warranty claims.
2. Inspect PCV System: The Positive Crankcase Ventilation (PCV) valve and associated system are a very common failure point on the 3.0T engine. A failing PCV system can lead to excessive crankcase vacuum, pulling oil into the intake manifold to be burned, and can also cause a lean condition. Look for oil residue in the intake tract or listen for a high-pitched whine from the engine.
3. Check Supercharger Oil Seals: The supercharger itself has internal seals that can degrade over time, allowing oil to be drawn into the intake charge and burned. This often doesn't produce visible smoke unless the failure is significant.
4. Turbocharger (if applicable, though S5 is supercharged): While your S5 has a supercharger, on other forced induction engines, turbocharger oil seals are a common source of internal oil consumption.
5. Piston Rings/Valve Seals (Worst Case): In more severe cases, worn piston rings or valve stem seals can lead to oil bypassing into the combustion chamber. This typically results in blue smoke, especially on startup or deceleration.

Common Causes:

• Failing PCV System: This is arguably the most common cause of internal oil consumption on the 3.0T.
• Supercharger Oil Seal Wear: Another frequent culprit for oil consumption without external leaks.
• Normal Engine Wear: Over time, some engines will naturally consume more oil as components wear.

When to See a Shop: If your documented oil consumption is consistently high (e.g., more than 1 quart every 1,500 miles) and you suspect a PCV or supercharger issue, it's time to visit an authorized Audi dealership or a specialist. They can perform a proper oil consumption test and use diagnostic tools to check for specific fault codes. While there might not be direct OBD-II codes for oil consumption itself, a failing PCV can sometimes trigger lean condition codes (P0171/P0174) or misfire codes if severe enough.