Compression Check: Testing and Inspection

Compression, Checking

• The compression can also be checked with a vehicle tester such as the vehicle diagnosis, testing and information system (VAS 5051 B).

Special tools, testers and auxiliary items required

• Adapter (V.A.G 1381/12)

• Compression tester (V.A.G 1763)

Test Conditions

• Engine oil temperature must be at least 30 °C.

• The battery voltage must be at least 12.7V.

• All electrical consumers such as, for example, lights and rear window defroster must be switched off.

Test Sequence

- Remove glow plugs from the corresponding cylinder. Refer to --> [ Glow Plugs ] Glow Plugs.

- Install adapter (V.A.G 1381/12) in place of the glow plugs.

- Check compression pressure using compression tester (V.A.G 1763).

• Using tester --> operating instructions.

- Activate starter until no further pressure increases are indicated by the Tester.

Compression

• New: 25.0 to 31.0 bar

• Wear limit: 19.0 bar

• Permissible difference between all cylinders: maximum 5.0 bar

- Install glow plugs from the corresponding cylinder. Refer to --> [ Glow Plugs ] Glow Plugs.

• By separating the connections, DTCs are stored to memory. After the test, check the fault memory and erase, if necessary.

- Read engine control module DTC memory and erase all DTC entries "Guided Functions".