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.

• 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.

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.