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Audi A6 C6: Oil Consumption Issues

Excessive oil consumption is a known problem among some Audi models. The C6 isn't immune, even if it's a low mileage vehicle.

By Kate Halse - April 19, 2016
Contributors: nielsn

This article applies to the Audi A6 C6 (2005-2010).

Oil consumption issues are a relatively common complaint among C6 owners. Several owners report seeing a low oil warning light between 25,000 and 80,000 miles; although, the problem can occur with just a few thousand miles on the odometer or over the 100,000 mile mark. While the problem is more prevalent among Audi owners with a 2.0T engine, it can also occur in Audi cars with a 3.0T engine. Before you bring your vehicle to the dealership for a potentially expensive repair, read on to find out more about potential causes of excessive oil consumption as well as possible solutions.

Component Breakdown

Oil Minimum Indicator Light

The oil minimum indicator light illuminates to let you know that the oil level is low. Your car automatically checks oil levels and is designed to alert you when it's time to add more oil. Several owners report having to top up with 1/2 to one quart of oil every 5,000 miles between oil changes. However, some vehicles require up to one quart of oil every 2,500 miles. At least one owner reports that, but according to the dealership, adding one quart of oil every 5,000 miles is normal and that it can take up to 25,000 miles for the rings to settle.

Figure 1. Some C6 owners report excessive oil consumption between intervals.

Misfires, Stumbling, and Running Rough

Symptoms of bad pistons and/or seals, both of which can get worn down over time, may include misfiring, stumbling or struggling, and generally running rough. There may also be burnt oil residue on the exhaust tips. In some cases the culprit is a bad breather valve. These issues can lead to excessive oil consumption.

Figure 2. Burnt oil residue may build up on the exhaust tip.

Oil Leaks

Fortunately, not every oil leak is a sign of a serious engine problem. In some cases the surrounding components can get worn out over time. A relatively common problem on 2.0T cars is a cracked valve cover. Some drivers report seeing smoke when driving uphill or merging onto a highway. If the issue isn't immediately obvious, it can help to perform a dye test to determine the source of the leak.

Figure 3. Smoke can be a symptom of an oil leak.

Scheduled Maintenance

Changing the oil according to Audi's specifications can help keep your A6 running strong. In general, the automaker suggests an initial oil change after the first 5,000 miles, then every 10,000 miles. Some A6 owners prefer to change the oil more frequently, such as every 5,000 to 7,000 miles. Audi recommends using a full synthetic oil for each oil change.

Common Question

Can driving habits affect oil consumption?

Several owners believe that driving habits can have an impact on oil consumption. For example, drivers who tend to have a heavy foot often report needing to top off the oil between scheduled intervals. Audi suggests gently breaking in the engine by avoiding heavy acceleration in the first 3,000 miles of ownership.

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