2013 Audi S8 Repair and Maintenance
A guide to problems, costs, maintenance and repair for your 2013 Audi S8
2013 Audi S8 ProblemsDecreased Power and Fuel Economy from Carbon Buildup
The 2007-2016 Audi S8 4.0TFSI and 5.2FSI direct injection engines are subject to carbon buildup in the intake system which can cause power loss, OBD codes and a check engine light, and a rough idle. In normal engines, the engine is cleaned by the gasoline flowing through the injectors and into the intake system, however, the S8 uses direct injection so gasoline does not flow through common carbon buildup areas.
The solution is to remove the intake manifold and professionally clean the intake manifold, intake ports on the cylinder head, and the intake valves. This may need to be done in as few as 20,000 miles.