Compression Check: Testing and Inspection

Compression, Checking

Special tools, testers and auxiliary items required

• Spark plug removal tool (3122 B)

• Torque wrench (5 to 50 Nm) (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 V.

• All electrical consumers such as, for example, lights and rear window defroster must be switched off.

• If vehicle is equipped with an air conditioning system, this must be switched off.

• Selector lever must be in "P" or "N" position.

Test sequence

- Remove ignition coils with power output stage --> [ Ignition Coils with Power Output Stage ] Service and Repair.

- Pull all connectors off from fuel injectors.

- Remove spark plugs using spark plug removal tool (3122B).

- Check compression pressure using compression tester (V.A.G 1763).

• Using compression tester --> Operating instructions.

- Have a second technician fully depress accelerator pedal and crank engine.

- Operate starter until tester shows no further pressure increase.

Compression pressure:

New: 10 to 13 bar pressure

Wear limit: 7.0 bar pressure

Permissible difference between all cylinders: 3 bar

- Install spark plugs using spark plug removal tool (3122B) and tighten to 30 Nm.

After test has ended:

- Connect Vehicle Diagnosis & Serv. System (VAS 5052).

- Perform vehicle system test "Guided Fault Finding".

- End vehicle system test in such a way that possibly existing DTC entries are automatically erased.

- Generate readiness code in conjunction with a road test.

Observe safety precautions that apply to road tests.

- Perform road test.

- After that perform vehicle system test again and repair any occurring malfunctions.