Compression Check: Testing and Inspection

Compression pressure, checking





Special tools
^ 3220 Flexible socket
^ VAG 1331 Torque wrench 5 to 50 Nm (3.7 to 37 ft. lbs.)
^ VAG 1318/11 Adaptor
^ VAG 1763 Compression tester

Test conditions
^ Engine oil temperature must be at 30°C (86°F) minimum.
^ Battery voltage must be at least 11.5 V.

- Remove engine cover.





- Disconnect 10-pin electrical connector for Fuel Cut -off valve -N109- (arrow) on Diesel injection pump.
- Disconnect connectors from glow plugs.
- Remove all glow plugs using 3220 flexible wrench.





- Thread in VAG 1381/12 adaptor in place of glow plugs.
- Check compression using VAG VAG 1763 compression tester.

Note: See operating instructions for correct use of compression tester.

- Operate starter until tester displays no further increase in pressure.

Compression pressure
new: 25 to 31 bar (362.5 to 449.5 psi)
Wear limit 19 bar (275.5 psi)
Permissible difference between all cylinders:
^ 5 bar (72.5 psi)

- Install glow plugs using 3220 flexible wrench. Tightening torque: 15 Nm (11 ft. lbs.)
- Check Diagnostic Trouble Code (DTC) memory:

Note: DTCs will be stored because the Diesel injection pump harness connector has been disconnected. Check and erase the DTC memory.

- Read readiness code.
If the DTC memory was erased or the engine control module is subject to low voltage with ignition ON, reset readiness code again.