One problem related to engine has been reported for the 1996 Audi A4. The most recently reported issues are listed below.
1996 Audi A4 interior of vehicle flooding. The consumer opened the front passenger door to find a significant amount of water on the floorboard of the vehicle (front and rear/approximately 32 gallons of water). They later found water around the battery and other engine parts within that area, which ultimately destroyed the wiring harness and transmission control unit. This problem occurred before. The problem originated from a design flaw that restricts water drainage from the engine compartment because of the malfunctioning of the rubber seal around the drainage hole below the battery. The engine drainage hole was not visible or accessible for routine maintenance.