The pressure data obtained during the measurement on each cylinder of a gasoline engine should not differ by more than 3 bar. If the pressure in one or more cylinders differs from the pressure in other cylinders by more than 3 bar, then this indicates a defect in the valves, wear of the piston rings or working surfaces of the cylinders, as well as the cylinder head gasket.
When performing a compression test, the temperature of the engine oil must be at least +30°C. At this oil temperature, the oil filter is quite warm to the touch. Warm up the engine if necessary.
1. Unscrew the bolts (see arrows in illustration) and remove the engine top cover.
5.1. Unscrew the bolts (see arrows) and remove the engine top cover
2. Remove the fastening clamps and disconnect the air duct (see arrows in illustration).
5.2. Remove the clamps and disconnect the air duct (see arrows)
3. Remove the tips from the spark plugs (see arrows in illustration) and unscrew the candles using a special candle wrench.
5.3. Remove the tips from the spark plugs (see arrows)
4. Disconnect the 5-pin plug 1 from the ignition coils (see illustration).
5.4. Disconnect the 5-pin plug 1 from the ignition coils
5. Disconnect the fuel injector plugs.
6. Screw the compression tester into the spark plug socket following the instructions for use.
7. Ask the assistant to keep the accelerator pedal pressed until the end of the test.
8. Allow the engine to complete about 8 revolutions until the increase in pressure recorded by the compression gauge stops. Read the pressure gauge readings.
9. Install the dismantled components in the reverse order of removal.
Attention! Disconnection of the plugs is registered by the engine control unit as a fault. In this regard, it is recommended that you contact the workshop to delete the recording as soon as possible.
Table of compression values
nominal value | limit value | |
Compression, bar | 9-14 | 7,5 |
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