2015 Audi A7 Problems: 5 Known Issues

On the 2012-2018 Audi A7 3.0T, owners and independent shops call the front bearing in the supercharger "nose cone" the most-reported supercharger wear point on the 3.0T supercharged V6. The A7 shares this engine with the A6, S4/S5 and Q5. The supercharger is a Roots-type unit made by Eaton. It sits in the valley between the cylinder banks and is driven by a belt off the crankshaft. Its front bearing supports the drive shaft and carries constant load from the belt. One shop says wear typically shows up between 100,000 and 160,000 km (about 60,000-100,000 miles). One parts guide gives 80,000-130,000 miles. Early on, a whine or grinding that rises with RPM may only be heard at cold start or under light load. As the bearing wears, the noise becomes constant and louder, and boost and power can drop. If the bearing is left to fail, the supercharger rotors can hit each other. That destroys the supercharger and can send metal debris into the intake. The 2016-2018 A7 uses the updated CREC version of the engine, which adds a magnetic clutch to the supercharger drive. Audi tells technicians that a click when this clutch engages is normal, and that the sound can change as mileage builds. So a clutch noise on its own does not mean the bearing has failed.

On the 2012-2023 Audi A7, all A7 models with direct-injection engines (2.0T, 3.0T supercharged) suffer from severe carbon buildup on intake valves. In direct-injection engines, fuel bypasses the intake valves, leaving them exposed only to oil vapors from the PCV system. These vapors bake onto valve backs as hard carbon deposits over 60,000-100,000 miles. Carbon restricts airflow, causing rough idle, misfires, hesitation, and power loss. In severe cases, carbon prevents valves from seating properly, causing compression loss and valve damage requiring engine replacement. Walnut blasting is the usual fix once heavy deposits are confirmed.

On the 2012-2015 Audi A7 3.0 TFSI, audi TSB 2039995/2 applies to 2012-2015 A7 vehicles with the 3.0 TFSI engine when a rattle lasts about one to three seconds on the first start of the day. Audi attributes the supported sound to one of the upper timing-chain tensioners and states that this brief condition does not damage the engine. This brief rattle is not a sign that the timing chain is about to jump.

On the 2012-2018 Audi A7 3.0T, the 3.0T V6 thermostat housing in the C7 A7 develops coolant leaks from the plastic housing and its O-ring seals. The housing sits in the engine valley beneath the supercharger and cracks or warps over thermal cycling. Coolant leaks onto the serpentine belt area and can cause belt slippage or overheating if coolant loss is significant.

On the 2014-2016 Audi A7 3.0L V6 TDI, the 2014-2016 A7 3.0 TDI was part of the Volkswagen Group 3.0-liter diesel emissions scandal. These cars contained undisclosed software that reduced NOx aftertreatment during normal driving, and they were covered by the Second Partial Consent Decree between Audi, the EPA, DOJ, CARB and the California Attorney General. EPA and CARB approved an emissions modification specifically for model year 2014-2016 Audi A6 Quattro, A7 Quattro, A8, A8L and Q5 diesels. The settlement required a recall of affected generation-2 vehicles. For the older generation-1 Touareg and Q7 diesels, Volkswagen had to offer buyback or lease termination and, if approved, an emissions modification alternative. This matters to any used A7 TDI buyer: an unmodified car may not pass emissions inspection in some states and carries a documented compliance history that must be checked.