Compression Check: Testing and Inspection

Compression Check

Special tools






^ 3122 B Spark plug wrench
^ T10029 Installation tool
^ V.A.G 1331 Torque wrench 5 to 50 Nm (3.7 to 37 ft. lbs.), or equivalent
^ V.A.G 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.

Engine code AEG






Engine codes AVH, AZG






- Remove fuse 32 from fuse panel.






- Remove sparkplug connectors using T10029 tool and place sparkplug wires aside.
- Remove spark plugs using 3122 B tool.
- In engines with engine code AEG fully depress accelerator pedal using a second technician.
- Check compression using V.A.G 1763 tester.

Note:

- Compression tester operation instructions = 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)

- 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.