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)

• Puller (T40039)

Procedure

• Engine oil temperature min. 30 °C.

• Battery voltage min. 12.5 V.

- Switch off ignition.

- Open the quick-release fasteners - 1 - and remove the front noise insulation.





- Disconnect electrical connector on Engine Speed (RPM) Sensor (G28) - arrow - at bottom of transmission.





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





- Remove bolts - arrows - and remove left air duct.





- Loosen the hose clamp - 1 - and remove the bolts - 2, 3 and 4 -.





- Remove left air filter upper section.

- Disconnect electrical connector - arrow - on Mass Air Flow (MAF) Sensor 2 (G246).





- Remove bolt - arrow - and remove power steering reservoir from bracket, hydraulic lines remain connected.





- Remove oil dipstick - 2 - from guide tube.





- Remove bolts - 1 - and - 3 -.

- Disconnect electrical connectors to ignition coils and press wiring harness to side.

- Remove bolts - arrows - and remove right air duct.





- Disconnect vacuum hose - 5 - from air guide hose.





CAUTION!
Hose connectors - 4 - must not be opened. Move the right air filter housing upper section, with the crankcase ventilation hose still connected, to the side.

- Loosen the hose clamp - 6 - and remove screws - 1, 2 and 3 -.

- Remove right air filter housing upper section.

- Disconnect electrical connector - arrow - on Mass Air Flow (MAF) Sensor (G70).





- Remove the air filter lower section form the side connection.





- Remove the air filter lower section upward - arrow -.

- Disconnect electrical connector - 1 - on Engine Coolant Level (ECL) Warning Switch (F66) at bottom of coolant expansion tank.





- Remove bolts - 2 - and - 3 - and lay aside coolant reservoir with connected coolant hoses - 4 - and - 5 -.

- Remove bolts - 1 - and - 2 -.





- Disconnect electrical connectors to ignition coils and press wiring harness to side.

- Remove all ignition coils using Ignition Coil Puller (T40039).





- Using Spark Plug Removal Tool (3122 B), remove spark plugs.

- Check compression using Compression Tester (V.A.G 1763).

• Using tester => operating instructions.

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

- Repeat procedure on each cylinder.





Assembling

Assembly is in reverse order of removal, note the following:

- Install the left air filter upper section and the right air filter housing.

- Install spark plugs.

- Faults have been stored in the engine control modules because the connectors were disconnected: perform a "generate readiness code" under "Guided Functions".

Tightening Specifications