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:
- Using the compression tester. Refer to 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. Refer to Engine control module Diagnostic Trouble Code (DTC) memory, interrogating and erasing , Adapting functions and components.
- Generate readiness code again if DTC memory has been erased or engine control module was disconnected from permanent positive. Refer to Adapting components and functions ; Adapting components and functions.