Compression Test

Compression test

Special tools:
115 8540 EXTENSION 115 8540 Extension
999 9689 COMPRESSION METER 999 9689 Compression Meter

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.

Ignition system





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.

Conditions




The engine compression must always be checked at wide open throttle (WOT) and the engine at operating temperature .

Preparations





Remove (applies to turbocharged engines):
- the charge air pipe over the engine to improve accessibility.
Seal the charge air pipe with paper wipe as illustrated.

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 999 9689 COMPRESSION METER 999 9689 Compression Meter
with extension sleeve 115 8540 EXTENSION 115 8540 Extension.






Install





Install:
- the spark plugs.
Tightening torque 30 Nm (22 lb.ft) .
- the ignition coils.
Tightening torque 10 Nm (7.4 lb.ft) .

Install





Install:
- the cover over the ignition coils.
Tightening torque 8 Nm (6 lb.ft) .
- the upper camshaft belt cover.
Tightening torque 8 Nm (6 lb.ft) .
- the disassembled connectors.

Applies only to turbocharged engines:

Install the charge air pipe.
Remove the seals.
Tighten the mountings and hose clamps.

Erase diagnostic trouble codes (DTCs) and check





Erase diagnostic trouble codes (DTCs)

Start the engine and check that it functions normally.
Use VIDA to vehicle communication to check which diagnostic trouble codes (DTCs) have been stored.
Erase the diagnostic trouble codes (DTCs).
Check the engine compartment and wipe it clean.