Compression Check: Testing and Inspection

Compression, Checking

• If ceramic sheathed element glow plugs are installed, check the idle stabilization control before removing the glow plugs vehicle diagnosis, testing and information system (VAS 5051B). Only if one or more cylinder(s) is/are noticeable at this point is the compression test warranted.

Special tools, testers and auxiliary items required

• SW 10 hex ball socket (3220)

• Torque wrench (V.A.G 1331)

• Adapter (V.A.G 1381/12)

• Compression tester (V.A.G 1763 )

Test Conditions

• Engine oil temperature at least 30° C

Test Sequence

- Remove the engine cover and, if present, remove the upper engine noise insulation => [ Engine, Removing ] Engine, Removing.

- Disconnect central connector for pump-injector units - 1 -.





• If ceramic sheathed element glow plugs are installed, always follow the information for removing and installing them => [ Glow Plugs ] Glow Plugs.

- Disconnect the connector strip - 2 - from the glow plugs.

- Remove all the glow plugs => [ Glow Plugs ] Glow Plugs.

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





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

• Using tester => operating instructions.

- Operate starter until tester shows no further pressure increase.

Compression Pressure

• New: 25 to 31 bar pressure

• Wear limit: 19 bar pressure

• Permissible difference between all cylinders: 5 bar

• If ceramic sheathed element glow plugs are installed, always follow the information for removing and installing them => [ Glow Plugs ] Glow Plugs.

- Install the glow plugs using the socket (3220 ).

Tightening specification: 15 Nm

- Check DTC memory of Engine Control Module (ECM), repair any stored malfunctions and then erase DTC memory => [ Engine Control Module, DTC Memory, Checking and Erasing ] Scan Tool Testing and Procedures.

• By disconnecting the central connection for the pump-injector unit, DTCs will be stored.