Compression Check: Testing and Inspection

Compression pressure, checking

Special tools, testers and auxiliary items required





^ Spark plug removal tool 3122 B





^ Compression tester V.A.G 1763

Requirements
^ Minimum engine oil temperature: 30°C
^ Battery voltage at least 12.5 V

Work sequence
- Switch ignition off.





- Remove fuse for Fuel Pump (FP) from socket - 28 -.





- Remove rear engine cover - arrows -.





- Remove front engine cover - arrows 1 and 2 -.





- Remove cover - 1 - in engine compartment (left side).





- Remove bolt from coolant reservoir - arrow -.
- Disconnect electrical wiring from Engine Coolant Level (ECL) Warning Switch -F66- and set aside coolant reservoir with coolant hoses - 1 - and - 2 - connected.





- Remove bolt - arrow - at oil dipstick guide tube.

Note: Guide tube remains inserted in upper part of oil pan.





- Remove cover - 1 - in engine compartment (right side).





- Disengage Evaporative Emission (EVAP) Canister Purge Regulator Valve -N80- - 1 - from air guide.
- Remove bolts - arrows -.
- Remove air guide - 2 -.

CAUTION: Fuel system is under pressure! Before opening system, place clean rags around the connection. Then release pressure by carefully loosening connection.





Engine code BHF
- Unscrew fuel hose from connection on fuel rail pipe by counterholding using an open-end wrench at hex head - 1 - and - 3- and unscrewing union nut - 2 -.





All:
- Disconnect electrical harness connector - 2 - from Evaporative Emission (EVAP) Canister Purge Regulator Valve -N80-.
- Disconnect electrical harness connector - 3 - at Mass Air Flow (MAF) Sensor -G70-.
- Disconnect hose - 1 - to Secondary Air Injection (AIR) pump.
- Disconnect air guide hose - 4 - at Mass Air Flow (MAF) sensor.
- Move wiring harness clear at air filter housing.
- Remove clip and remove air filter housing with Mass Air Flow (MAF) sensor.





- Remove bolts - 5 - and - 6 - on left cylinder head.
- Disconnect electrical harness connectors - 1 to 4 -.
- Remove ignition coils - arrows -.

Note: Extractor T40039 can be used for ignition coil removal.





- Remove bolts - 5 - and - 6 - on right cylinder head.
- Disconnect electrical harness connectors - 1 to 4 -.
- Remove ignition coils - arrows -.

Note: Extractor T40039 can be used for ignition coil removal.

- Use spark plug removal tool 3122 B to remove spark plugs.
- Open throttle fully.
- Check compression using compression tester V.A.G 1763.

Note: Using compression tester tester operating instructions.

- Have a second technician press accelerator pedal completely and at same time operate starter long enough until pressure increase no longer appears on tester.

Compression values








Assembly is performed in reverse order of removal. Note the following:
- Secure fuel hose to connection on fuel rail pipe by counterholding using an open-end wrench at each hex head - 1 - and - 3 - and tightening union nut - 2 - to 22 Nm.

The following work step must be performed after the engine compression test:
- As a final step, use Vehicle Diagnosis, Testing and Information System VAS 5051 A to check DTC memory of Engine Control Module (ECM) and erase it, since malfunctions were stored by removing a fuse and disconnecting electrical harness connectors.

Tightening torques