Compression Check: Testing and Inspection

Compression, Checking

Special tools, testers and auxiliary items required

• Spark Plug Removal Tool (3122 B)

• Puller for Ignition Coil (T10095 A)

• Assembly Tool (T10118)

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

• Compression Tester (V.A.G 1763)

Test Conditions

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

• The battery voltage must be at least 11.5 volts.

• All electrical consumers such as, for example, lights and the rear window heater, must be turned off.

• If the vehicle is equipped with Air Conditioning (A/C), it must be turned off.

• The selector lever must be in either the "P" or "N" positions.

Test Sequence

- Remove the fuse for the fuel pump control module.

The voltage supply for fuel pump activation is interrupted when the fuse is removed.

- Remove the ignition coil wiring harness cover strip in the - direction of the arrows -.






- Place the assembly tool (T10118) on the locking button - arrow - and carefully pull the connector up.






- Slide the puller for ignition coil (T10095 A) on from the straight side of the connector in the - direction of the arrow - and pull out the ignition coil with power output stage.






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

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

• Using the tester, refer to the operating instructions.

- Have a second technician crank the engine long enough until the tester shows there is no increase in pressure.

Compression Pressure:






- Install the spark plugs using the spark plug removal tool (3122 B) and tighten them to 18 Nm.

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

After the procedure is completed:

- Connect the vehicle diagnostic tester.

- Perform the vehicle system test in "Guided Fault Finding".

- End the vehicle system test in such a way that possibly existing Diagnostic Trouble Code (DTC) entries are automatically erased.

- Generate a readiness code in conjunction with a road test.

Observe the safety precautions that apply to road tests.

- Then, perform a vehicle system test again and repair any occurring malfunctions if necessary.