Operation CHARM: Car repair manuals for everyone.

Compression Check: Testing and Inspection






Compression, Checking

Special tools, testers and auxiliary items required

• Spark Plug Removal Tool (3122 B)

• Ignition Coil Puller (T40039)

• Compression Tester (V.A.G 1763)

Test Sequence

• Engine oil temperature min. 30 °C (86 °F)

• Battery voltage at least 12.7 V

- Remove the engine cover - arrows -.






- Remove the bolts on the ignition coil connector strip.

- Release the connector - arrows - and disconnect all the connectors at the same time from the ignition coils.






- Remove the ignition coils with the (T40039).






- Remove the spark plugs using a (3122 B).

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

• Using tester: Operating Instructions.

- Operate starter until tester shows no further pressure increase.

Compression Pressure:






- Install the spark plugs.

- Install the ignition coils with output stages.

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

- Check the engine control module DTC memory using the vehicle diagnosis, testing and information system VAS 5051 under "Guided Fault Finding.