Compression Check: Testing and Inspection

Compression pressures, checking





Special tools equipment
^ 3122 B Spark plug wrench
^ T10112 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°C.
^ 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 code AEG





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

Engine codes AVH, AZG, BBW, BEV





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

Continued for all engines





- Pull fuse No 32 out of fuse holder.

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

- Disconnect connectors from outer injectors.
- Pull spark plug connectors off with tool T10112
- Remove spark plugs with spark plug socket 3122B.
- Check compression pressures using compression tester V.A.G 1763 and adapter V.A.G 1763/6.

Note: Compression tester operating instructions.

Vehicles with throttle (accelerator) cable
- Have a second technician fully depress accelerator pedal.

Continuation for all engines
- Have a second technician 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.
- Generate readiness code again if DTC memory has been erased or engine control module was disconnected from permanent positive.