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Home >> Saab >> 2005 >> 9-2X F4-2.0L Turbo >> Repair and Diagnosis >> Maintenance >> Tune-up and Engine Performance Checks >> Compression Check >> Testing and Inspection
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Compression Check: Testing and Inspection

Compression

Inspection

CAUTION: After warming-up, engine becomes very hot. Be careful not to burn yourself during measurement.

1. After warming-up the engine, turn the ignition switch to OFF.
2. Make sure that the battery is fully charged.
3. Release the fuel pressure.
4. Remove all the spark plugs.
5. Fully open the throttle valve.
6. Check the starter motor for satisfactory performance and operation.
7. Fix the compression gauge securely against spark plug hole.

NOTE: The screw of screw-in type compression gauge (put into cylinder head spark plug hole) should be less than 18 mm (0.71 inch) long.

8. Crank the engine by means of starter motor, and then read the maximum value on the gauge when the gauge needle is steady.





9. Perform at least two measurements per cylinder, and make sure that the values are correct.

Compression (at 200 - 300 rpm):
Standard 981 - 1,177 kPa (10 - 12 kgf/cm2, 142 - 171 psi)

Difference between cylinders 2
Less than 49 kPa (0.5 kgf/cm2, 7 psi)
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