Compression Pressures, Checking

Compression pressures, checking





Special tools, testers and auxiliary items required
^ Spark plug removal tool 3122 B
^ Torque wrench V.A.G 1331
^ Compression tester V.A.G 1763

Test conditions





^ Engine oil temperature must be at least 30°C.
^ Battery voltage must be at least 11.5 Volts.
^ All electrical consumers, such as lights and rear window defroster must be switched off.
^ If vehicle is equipped with an A/C system, it must be switched off.

Test sequence
- Remove fuse No. 32 from fuse holder.

Note: Removing fuse No. 32 interrupts the voltage supply to the injectors.

- Disconnect the ignition coil connectors.
- Remove ignition coils with power output stage.
- Remove spark plugs using spark plug removal tool 3122 B.
- Check compression using compression tester V.A.G 1763.

Note: Using tester Operating instructions.

- Have a second technician operate the starter.
- Operate starter until tester shows no further pressure increase.

Compression pressure:
New engine: 10 to 14 bar positive pressure
Wear limit: 7.0 bar pressure
Permissible difference between all cylinders: max. 3 bar

- Install spark plugs and ignition coils.
- Check DTC memory of Engine Control Module (ECM), repair any stored malfunctions and then erase DTC memory.
- After erasing DTC memory, readiness code must be generated again.