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)
• Ignition Coil Puller (T40039)
Procedure
• Engine oil temperature at least 30 °C (86 °F)
• Battery voltage at least 12.5 V.
- Remove the rear engine cover - top arrows -.
- Remove the strut tower brace.
- Remove the bolts - arrows -.
- Disconnect the electrical connector on the Engine Coolant Level (ECL) warning switch (F66) and lay the coolant reservoir aside with the coolant hoses - 1 and 2 - connected.
• Be careful not to bend the coolant hose - 2 -.
- Remove the bolts - arrows - and disconnect the electrical connectors to the ignition coils on the left cylinder head.
- Press the electrical wiring harness down slightly.
- Disconnect the electrical connector - 3 - to the fuel injectors on the rear of the left cylinder head.
• Ignore - 1, 2 and 4 - and - arrows -.
- Remove the air filter housing.
- Remove the bolts - arrows - and disconnect the electrical connectors to the ignition coils on the right cylinder head.
- Press the electrical wiring harness to the side.
- Disconnect the electrical connector - 3 - to the fuel injectors on the rear of the right cylinder head.
• Ignore - 1, 2 and 4 - and - arrows -.
- Remove all the ignition coils with the (T40039).
- Remove the spark plugs with the (3122 B).
- Check compression pressure using the (V.A.G 1763).
• Using tester see operating instructions.
- Have a second technician press the accelerator pedal down all the way while operating the starter until the pressure increase is no longer displayed on the tester.
Assembling
• For the correct tightening specifications, refer to => [ Cylinder Head Overview ] Cylinder Head Overview.
Assemble in reverse order of disassembling. Note the following:
- Install spark plugs.
- Install the air filter housing.
- Install the tower brace.
- If the electrical connectors were disconnected and the engine was started, then the malfunctions have been stored in the engine control module. "Generate readiness code" in "Guided Functions" using the vehicle diagnostic tester.