Compression Check: Testing and Inspection
Compression, Checking
Special tools, testers and auxiliary items required
• Spark Plug Removal Tool (3122 B)
• Ignition Coil Puller (T40039)
• Compression Tester (V.A.G 1763)
Test Sequence
• Engine oil temperature min. 30 °C (86 °F)
• Battery voltage at least 12.7 V
- Disconnect the electrical connector on the mass airflow (MAF) sensor (G70) - 3 -.
- Open clips - 1 and 2 - and remove air guide hose from MAF sensor.
- Remove front air intake connector on lock carrier - 4 -.
- Remove engine cover.
- Remove the ignition coils with power output stage.
- Remove spark plugs, using the (3122 B).
- Disconnect 8-pin connector from fuel injectors.
- Check compression using the (V.A.G 1763) and adapter (V.A.G 1763/6).
• Using tester operating instructions.
- Operate starter until tester shows no further pressure increase.
Compression Pressure:
- Install sparks plugs.
- Install ignition coils with power output stage.
• By separating the connections, Diagnostic Trouble Codes (DTCs) are stored to memory. After the test, check the fault memory and erase, if necessary.
- Read out ECM DTC memory. Vehicle diagnostic, testing and information system VAS 5051 in "Guided Fault Finding" function.