The rear main seal in the engine of some Audi vehicles is failing prematurely and requiring replacement with as few as 26,000 miles. Customers may have a claim for defective design.

In addition, Audi appears to be denying some replacements that would otherwise be covered under warranty if users have modified their vehicles at all, even in unrelated ways, potentially in violation of the Magunsson-Moss Warranty Act.

Affected models include the 2018 S4, the 2013 S4, and some A4 models. The same issue appears to be affecting several Volkswagen vehicles. Volkswagen is the parent company to Audi and appears to use the same parts in some areas of the vehicles.  

In 2014, Volkswagen and Audi collectively agreed to settle a class action lawsuit alleging that the engines in Audi A4s and A5s as well as Volkswagen vehicles between 2007 and 2013 were defective.