Compression, Checking
Special tools and workshop equipment required
- Spark Plug Removal Tool :3122B
- Compression Tester Kit :VAG1763
- Compression Tester Kit - Adapter 5A :VAG1381/5A
- Fuel Injection Gauge Kit - Adapter VAG1381/1 :VAG1381/1
- Vehicle Diagnostic Tester
Test Sequence
- Engine oil temperature at least 30 °C (86 °F).
- Battery voltage at least 12.7 V.
Preliminary work may be required depending on the model. Refer to COMPRESSION PRESSURE, CHECKING .
-- Remove the ignition coils with power output stages. Refer to IGNITION COILS WITH POWER OUTPUT STAGES, REMOVING AND INSTALLING .
-- Remove the spark plugs using the :3122B .
-- Check the compression using the :VAG1763 , :VAG1381/1 and :VAG1381/5A . Information on using the tester. Refer to the Operating Instructions.
- The help of a second technician is necessary for the following step.
-- Have a second technician operate the starter until the tester stops displaying a pressure increase.
| Compression Pressure | Pressure |
|---|---|
| New | 11.0 to 14.0 bar (159.54 to 203.05 psi) |
| Wear limit | 7.0 bar (101.52 psi) |
| Maximum difference between cylinders | 3.0 bar (43.51 psi) |
Assembling
-- Install the spark plugs. Refer to OVERVIEW - IGNITION SYSTEM .
-- Install the ignition coils with power output stages. Refer to IGNITION COILS WITH POWER OUTPUT STAGES, REMOVING AND INSTALLING .
-- Delete the DTC memory entries in the engine control module that have occurred during the test. Refer to Vehicle Diagnostic Tester.
There are additional procedures depending on the model. Refer to COMPRESSION PRESSURE, CHECKING .