Compression, Checking

WARNING: This page is about a different car, the 2010 Volkswagen Jetta and 2009 Volkswagen Jetta. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

The compression can also be checked using a vehicle diagnostic tester such as the vehicle diagnosis, testing and information system VAS 5051 B.

Special tools and workshop equipment required

Adapter V.A.G 1381/12
Compression Tester V.A.G 1763

Test Conditions

Engine oil temperature must be at least 30 °C (86 °F).
The battery voltage must be at least 12.7 volts.
All electrical consumers such as, for example, lights and rear window defogger, must be turned off.

Test Sequence

-- Remove the glow plug from the corresponding cylinder. Refer to GLOW PLUGS .

-- Install the adapter V.A.G 1381/12 in place of the glow plug.

-- Check the compression pressure using compression tester V.A.G 1763.

NOTE:

Using the tester, refer to the tester operating instructions.

-- Operate the starter until the tester show there is no further increase in pressure.

Compression Pressure

New: 25.0 to 31.0 bar
Wear limit: 19.0 bar
Permissible difference between all cylinders: maximum 5.0 bar

-- Install the glow plug to the corresponding cylinder. Refer to GLOW PLUGS .

NOTE:

By disconnecting the connectors, Diagnostic Trouble Codes (DTCs) are stored to memory. After the test, check the fault memory and erase, if necessary.

-- Read the Engine Control Module (ECM) DTC memory and erase all DTC entries. Refer to "Guided Functions" in the vehicle diagnostic tester.