Compression, Checking

Compression, checking

Special tools and Equipment






^ 3122 B Spark plug wrench
^ 3277 A Installation tool
^ VAG 1331 Torque wrench 5 to 50 Nm (3.7 to 37 ft. lbs.)
^ VAG 1763 Compression tester

Test conditions

^ Engine oil temperature must be 30° C minimum.
^ Battery voltage must be 11.5 V Minimum.

Work Sequence

- Remove engine cover.
- Disconnect harness connector -arrow- for ignition coil power output stage.

Only engine code AEG






Engine code AVH, AZG







- Remove fuse 32 from fuse panel.






- Pull connectors off outer injectors.
- Remove spark plug connectors using TI 0029 tool and place spark plug wires aside.
- Remove spark plugs using 3122 B tool.
- Have a second technician operate starter.
- Vehicles with engine code AEG: fully depress accelerator pedal using a second technician.
- Check compression using VAG1763 tester.

Note:
- For compression tester operation instructions see the Tester Operators Manual.

- Crank starter until tester shows no further increase in pressure.
- Compression pressure:

- New: 10 to 13 bar(145 to 189 psi)

- Wear limit: 7.5 bar (109 psi)

- Maximum permissible difference between all cylinders:

- 3 bar (43.5 psi)

- Finally, erase engine control module DTC memory because pulling off injector connectors will have caused a DTC to be recorded.
- Check Diagnostic Trouble Code memory.
- Check Readiness code.
- Reset Readiness code after DTCs are corrected, Engine Control Module (ECM) is subject to low voltage with ignition on, or ECM is replaced.