COMPRESSION TEST
Special tools
see 1158540
see 9999689
Note. As the illustrations in the information are used for different model years and / or models, certain variations may occur. However, the essential information in the illustrations is always correct.
Scheme 1440
| CAUTION | The ignition system operates at high ignition charges and produces dangerous voltages in both the low and high voltage circuits. There is dangerous voltage throughout the entire ignition system including connectors etc. |
Scheme 1441
The engine compression must always be checked at wide open throttle (WOT) and the engine at operating temperature .
Scheme 1442
Remove (applies to turbocharged engines)
- the charge air pipe over the engine to improve accessibility. Seal the charge air pipe with paper wipe as shown in the illustration.
Remove
- the upper camshaft belt cover.
- the cover over the ignition coils.
- the ignition coils. Mark up and put to one side without disconnecting the connectors.
- the spark plugs.
Note. Separate the connector for the engine speed (RPM) sensor.
COMPRESSION TESTING
Note. Compression testing should always be carried out at wide open throttle (WOT) and with the engine at operating temperature. Diagnostic trouble codes (DTCs) will be stored because the engine speed (RPM) sensor and (where applicable) the camshaft position (CMP) sensor have been disconnected.
Have an assistant hold the accelerator pedal (AP) depressed at wide open throttle (WOT) during the compression test.
The starter motor is activated with the ignition key.
The ignition must be switched off after each cylinder has been compression tested.
Note. It will no longer be possible to control the throttle if the ignition is on for longer than 2 minutes. The throttle function is controlled by the control module.
Use compression meter see 9999689
with extension sleeve see 1158540 .
| Engine type | Normal value MPa |
|---|---|
| Turbo | 1.1 - 1.3 |
| Turbo type LT | 1.2 - 1.4 |
| Normally aspirated engine | 1.3 - 1.5 |