Compression Check: Testing and Inspection
Compression, Checking
Special tools, testers and auxiliary items required
• Spark Plug Removal Tool (3122 B)
• Compression Tester (V.A.G 1763)
• Hose Clamps Up to 25 mm Dia. (3094)
• Pry Lever - Remove Outside Mirror (80-200)
• Puller for Ignition Coil (T10094)
Conditions
• Engine oil temperature min. 30 °C (86 °F).
• Battery voltage at least 12.5 V.
Sequence
- Turn off ignition.
- Remove fuse for Fuel Pump (FP) from socket "28".
- Remove rear engine cover - arrows -.
- Remove front engine cover - arrow 1 and arrows 2 -.
- Clamp off coolant hose - 2 - using (3094) and disconnect from coolant expansion tank.
- Remove coolant expansion tank - arrow -.
- Disconnect electrical connection from Engine Coolant Level (ECL) Warning Switch (F66) at bottom of the coolant reservoir and set aside coolant reservoir with coolant hoses - 1 and 3 - connected.
- If necessary, seal the connection using an appropriate plug.
- Remove bolt - arrow - at oil dipstick guide tube.
• Guide tube remains inserted in upper oil pan.
- Remove air filter cover - 2 -.
- Remove the air duct - 1 -.
• To pull out the clips - arrows -, use (80-200).
• If necessary, use silicon-free spray lubricant to facilitate removal.
- Unclip the fuel hose - 1 -.
- Separate electrical connector - 2 - from Mass Airflow (MAF) sensor.
- Disconnect MAF sensor from the intake air duct - 3 -.
- Remove upper section of the air filter housing with MAF sensor - arrows -.
- Remove bolts - 5 and 6 - on left cylinder head.
- Disconnect electrical harness connectors - 1 to 4 -.
- Remove ignition coils - arrows -.
• (T10094) can be used for removal.
- Remove bolts - 5 and 6 - on the right cylinder head.
- Disconnect electrical harness connectors - 1 to 4 -.
- Remove ignition coils - arrows -.
• (T10094) can be used for removal.
- Remove the spark plugs with the (3122 B).
- Open throttle valve completely.
- Check compression pressure using the (V.A.G 1763).
• Using tester see operating instructions.
- Operate starter until tester shows no further pressure increase.
Compression Pressure:
Assembly is performed in the reverse order of removal, noting the following:
- Install sparks plugs.
The following work step must be performed after the engine compression test.
- As a final step, check DTC memory of Engine Control Module (ECM) and erase it see vehicle diagnostic tester, since malfunctions were stored by removing the fuse.
Tightening Specifications
* Insert using locking compound.