See Figure 1
Volvo identifies its engines by a type or family, using a combination of letters and numbers. Examples of a type number are B20B, B21F, or D24T. These family designations will be used throughout this guide. Each engine within a particular family is further identified by its engine number. These engine numbers are coded to show emission type, transmission match (manual or automatic), and other detailed information. While you can work from this guide knowing only the engine type, replacement parts must be ordered using the exact engine number.
Start by looking at the vehicle number and selecting the engine type codes from the proper positions. Refer to the chart below to identify the engine family. Write the family designation down so that it's available any time you need it.
The engine number, part number and serial number are located on the left side of the engine on all models. On the B20, B30 engines, the number is located on the left side front of the engine. On the B21 and B23 series engines, the last three digits of the engine number are printed on a label on the timing belt cover. On the B230 series engines, the serial number is a six-digit number located on the camshaft drive cover and is also stamped on the cylinder block, behind the distributor.
On the B27, B28 engines, the number is located low on the block. The B280 engines have the number stamped on the cylinder block. The early type is located between the cylinder banks toward the rear, and the later type is located on the front right side, between the intake manifold and the water pump.
On the D24 series diesel engines, the engine number is stamped on the block underneath the vacuum pump.