Compression Check: Testing and Inspection

Compression Pressure, Checking

Special tools, testers and auxiliary items required

• Spark Plug Removal Tool (3122 B)

• Ignition Coil Puller (T40039)

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

• Compression Tester (V.A.G 1763) with Adapter (V.A.G 1763/6)

Test Conditions

• The engine oil temperature must be at least 30 °C (86 °F).

• Battery voltage is at least 12.7 volts.

Test Sequence

• Follow all safety precautions. Refer to => [ Safety Precautions ] Safety Precautions.

- Remove the ignition coils with the power output stages. Refer to => [ Ignition Coils with Power Output Stages ] Service and Repair.

- Remove the spark plugs using the spark plug removal tool (3122 B).

- Check the compression using the compression tester (V.A.G 1763) and the adapter (V.A.G 1763/6).

• Using the tester, refer to the operating instructions.

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

Compression Pressure

• Mew: 11.0 to 14.0 bar pressure

• Wear limit: 7.0 bar pressure

• Permissible difference between all cylinders: Max. 3 bar

- Install the spark plugs. Refer to => [ Ignition System Component Overview ] Service and Repair.

- Install the ignition coils with power output stages. Refer to => [ Ignition Coils with Power Output Stages ] Service and Repair.

• By disconnecting the connections, Diagnostic Trouble Codes (DTCs) are stored to memory. After the test, check the fault memory and erase, if necessary.

- Check the Engine Control Module (ECM) DTC memory and erase all DTC entries which may have occurred during the assembly. Refer to "Guided Functions" in the vehicle diagnostic tester.

• Generate a readiness code if the DTC memory was erased. Refer to "Guided Functions" in the vehicle diagnostic tester.