Compression, Checking

Special tools and workshop equipment required

Spark Plug Removal Tool:3122B

Fig 1: Identifying Spark Plug Removal Tool 3122B
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Compression Tester Kit:VAG1763

Fig 2: Compression Tester Kit VAG 1763
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Adapter:VAG1763/13 , not illustrated

Test Sequence

-- Remove the engine cover. Refer to ENGINE COVER, REMOVING AND INSTALLING .

-- Disconnect the fuel injector connector -arrow-.

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-- Remove the ignition coils. Refer to IGNITION COILS, REMOVING AND INSTALLING .

-- Remove the spark plugs using the Spark Plug Removal Tool:3122B .

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-- Install the Adapter:VAG1763/13 as shown in the respective spark plug hole and connect the Compression Tester Kit:VAG1763 .

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-- Check the compression using the Compression Tester Kit:VAG1763 . Refer to the Operating Manual.

-- Have a second technician operate the starter until the tester stops displaying a pressure increase.

-- Repeat the procedure on each cylinder.

Compression Pressure	Pressure
New	16.0 to 19.0 bar (232.06 to 275.57 psi)
Wear limit	12.0 bar (174.04 psi)
Maximum difference between cylinders	3.0 bar (43.51 psi)

TIP:

If the test with the Compression Tester Kit:VAG1763 does not lead to a clear result there are two additional tests.

In addition to the compression test a pressure test can be performed with the Pressure-Loss Tester:VAS522001 . The procedure for this is described in the operating instructions for the Pressure-Loss Tester:VAS522001 .
As an additional test the CO2 content in the coolant expansion tank can be measured. A raised CO2 content in the cooling system indicates a leak between the combustion chamber and the cooling system. The CO2 content can be determined using the CO2 Coolant Tester:VAS531009 . The procedure for this is described in the operating instructions of the CO2 Coolant Tester:VAS531009 .

Assembling

-- Install the spark plugs. Refer to OVERVIEW - IGNITION SYSTEM .

-- Install the ignition coils. Refer to IGNITION COILS, REMOVING AND INSTALLING .

-- Install the engine cover. Refer to ENGINE COVER, REMOVING AND INSTALLING .

-- Delete the DTC memory entries in the Engine/Motor Control Module that have occurred during the test using the Vehicle Diagnostic Tool.