Engine Identification

For A8 models with the 3.7L V8 or 4.2L V8 engine and Engine Codes AEW and ABZ the engine code letters and serial number are stamped on the left side of the cylinder block (arrow), directly above the power steering pump. See Fig 1. In addition, an adhesive label with engine code letters and serial number is affixed to the toothed belt guard. The engine code letters are also listed on the vehicle data plate.

Fig 1: Locating Engine Code (3.7L AEW & 4.2L ABZ)

Courtesy of AUDI OF AMERICA, INC.