Compression Check: Testing and Inspection

Compression Pressure, Checking

Special tools, testers and auxiliary items required

• Compression Tester (V.A.G 1763)

Requirements

• The engine oil temperature is approximately 80 °C (176 °F)

• Battery voltage is a minimum of 12.5 volts.

Procedure

- Remove the engine cover. Refer to => [ Engine Cover ] Engine Cover.

- Disconnect the connectors from the glow plugs.

- Disconnect the connector - 1 - from the fuel pressure regulator valve (N276) on the cylinder bank 1 (right side) fuel rail.






- In order to reduce the fuel pressure in the rail, start the engine briefly.






- Remove the glow plugs. Refer to => [ Glow Plugs ] Service and Repair.

- Install the adapter (V.A.G 1763/8) in place of the glow plugs and connect the compression tester (V.A.G 1763).






• Using the tester, refer to the operating instructions.

- Have a second technician operate the starter until the tester does not show the pressure increasing any further.






Install in the reverse order of removal. Note the following:

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

- Check the Engine Control Module (ECM) Diagnostic Trouble Code (DTC) memory and erase it to clear any faults stored from disconnecting the connectors. Refer to the vehicle diagnostic tester.