Engine Number

The engine number (engine code and serial number) -arrow- is located at the front on the engine/transmission joint.

Fig 1: Identifying Engine Number Location
Courtesy of AUDI OF AMERICA, LLC
In addition, a sticker with engine codes and serial number is affixed to the toothed belt guard.
Engine codes beginning with C are four-digit.
The first 3 digits of the engine code stand for displacement and the mechanical structure of the engine. They are stamped in the cylinder block, including the serial number.
The fourth digit describes the engine output and torque and depends on the engine control module.

NOTE:

The 4-digit engine code is on the type plate, vehicle data label and engine control module.

Locations of the type plate and vehicle data label. Refer to 03 MAINTENANCE, DIAGNOSIS .