Compression Check: Testing and Inspection

Compression Test

Special tools, testers and auxiliary items required

• Socket Insert AF 12 for Glow Plugs 4-Cyl.TDI CR (VAS 6454)

• Compression Tester (V.A.G 1763)

• Adapter (V.A.G 1763/8)

• Torque Wrench (5-50 Nm) (V.A.G 1331)

Test Conditions

• The engine oil temperature must be a minimum of 30 °C (86 °F).

Test Sequence

- Disconnect the connectors from the fuel injectors.

- Remove the glow plug, refer to => [ Glow Plugs ] Service and Repair.

- Install the adapter (V.A.G 1763/8) in place of the glow plug.

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

• Using the tester, refer to the operating instructions.

- Operate the starter until the tester no longer indicates that the pressure is increasing.

Compression pressure:

New: 25 to 31 bar excess pressure

Wear limit: 19 bar pressure

Permissible difference between all cylinders: 5 bar

- Install the glow plug. Refer to => [ Glow Plugs ] Service and Repair.

- Check the Engine Control Module (ECM) Diagnostic Trouble Code DTC) memory. Refer to the vehicle diagnostic tester.

• By disconnecting the fuel injector connectors, faults will be stored in the DTC memory. Query the fault memory and erase it, if necessary.