Compression Check: Testing and Inspection

Compression pressures, checking
Special tools equipment





- 3122 B Spark plug wrench
- T101 12 Removal tool
- V A G 1331 Torque wrench (5 to 50 Nm)
- V A G 1763 Compression tester

Requirements
- Engine oil temperature must be at least 30°.
- Voltage supply OK.
- All electrical consumers, e.g. lights and rear window defroster must be switched off.
- If the vehicle is equipped with air conditioning, this must be switched off.
- On models with an automatic transmission, selector lever in position "P" or "N"

Work sequence
- Remove engine cover.





Engine: AEG
- Disconnect black 6-pin connector from ignition coil with final output stage (arrow).





Engines: AVH, AZG, BBW, BEV
- Disconnect black 6-pin connector from ignition coil with final output stage (arrow).





Engines: APK, AQY, BHP
- Disconnect 4-pin connector -1- off final output stage for ignition coils -2





Engines: BEJ, BER
- Disconnect black 6-pin connector from ignition coil with final output stage (arrow).





Continue for all engines
- Pull fuse out of fuse holder.
Engines: AEG, AVH, AZG, BBW, BEJ, BER, BEV, BHP: Fuse No. 32

Note: Removing the fuse 32 interrupts the voltage supply to the injectors.

Engines: APK, AQY: Fuse No. 28 fuel pump.
- Disconnect connectors from outer injectors.
- Pull spark plug connectors off with tool T101 12
- Remove spark plugs with spark plug socket 31 22B.
- Check compression pressures using compression tester V.A.G. 1763 and adapter V.A.G. 1763/6.

Note: Using the compression tester - Operating instructions.

Models with throttle (accelerator) cable
- Use a second technician to fully depress accelerator pedal.

Continuation for all engines
- Use a second technician to operate starter motor.
- Operate starter until tester shows no further pressure increase.

Compression pressure values:
New: 10 to 13 bar
Wear limit: 7.5 bar
Permissible difference between all cylinders: 3 bar
- Adapt engine control module to throttle valve control module, Refer to Adapting functions and components.
- Generate readiness code again if DTC memory has been erased or engine control module was disconnected from permanent positive.