Compression Test directly from Bentley Manual.
1. Release locking pins for engine cover by turning 90 degrees. Remove the cover completely.
2. Warm up engine until it is a minimum of 30 degrees Celsius (60 degrees F) and switch ignition off.
3. Disconnect 4 pin harness connectors from all ignition coils and
remove ignition coils (Place them in a way that you know which ones are for each cylinder). If you have an AWD engine code unbolt the coils from the head and remove the vacuum reservoir (canister).. If you have an AWW or AWP engine code just remove the coils.
4. Use compressed air to clear area around spark plugs. Remove all spark plugs and lay aside in an order that you remember which one goes to each cylinder.
5. Remove fuse #32 for voltage supply to injectors (in car)
6. Fit compression tester into spark plug hole.
7. Have a helper - Depress clutch pedal fully, Put transmission in either park or neutral, Depress the accelerator pedal to floor, Crank engine over with starter motor. Crank a minimum of 4 to 5 revolutions.
8. Record readings from each cylinder in gauge and repeat procedure for each cylinder.
9. Compare readings to these specifications. New Cylinders (145-203 psi) Wear limit (102 psi) Maximum difference between cylinders 44 psi
10. When all cylinders have been checked, reinstall spark plugs and ignition coils, connect harness connectors for coils and reinstall fuse #32. Reinstall fuse panel.
NOTES Cranking engine with ignition system disabled and components disconnected will cause Diagnostic trouble codes (DTC's) to be stored in engine management system memory. You must clear these codes.
Tightening Torques Spark plug to cylinder head - 22 ft/lbs
Tightening Torques Ignition coil to cylinder head (If bolt down coils) - 7 ft/lbs.