Compression, Checking
Special tools and workshop equipment required
- Compression Tester Kit: VAG1763
- Spark Plug Socket Adapter 3/8" : VAS6919 , not illustrated
Procedure
- The engine oil temperature must be at least 30 °C (86 °F)
- Battery voltage at least 12.5 V.
-- Remove the fuse for the Fuel Pump Control Module -J538-. Refer to the appropriate Wiring Diagram.
-- Remove the ignition coils. Refer to IGNITION COILS, REMOVING AND INSTALLING .
-- Remove the spark plugs using the Spark Plug Socket Adapter 3/8": VAS6919 .
With Compression Tester Kit - Adapter: VAG1763/12 :
-- Install the Compression Tester Kit: VAG1763 as shown in the corresponding spark plug connectors.
With Compression Tester Kit - Adapter: VAG1763/12A :
-- Install the Compression Tester Kit: VAG1763 as shown in the corresponding spark plug connectors.
Continuation:
-- Check the compression using the Compression Tester Kit: VAG1763 . Refer to the Operating Manual.
- The help of a second technician is necessary for the following step.
-- Have a second technician press the accelerator pedal all the way down and operate the starter at the same time, until a pressure increase is no longer displayed on the tester.
-- Repeat the procedure on each cylinder.
| Compression Pressure | Pressure |
|---|---|
| New | 10.5 to 15.5 bar (145.03 to 224.80 psi) |
| Wear limit | 8.5 (123.28 psi) |
| Maximum difference between cylinders | 3 bar (43.51 psi) |
The assembly is done in reverse sequence while observing the following:
-- Install the spark plugs. Refer to OVERVIEW - IGNITION SYSTEM .
-- Install the ignition coils. Refer to IGNITION COILS, REMOVING AND INSTALLING .
-- Install the fuse for the Fuel Pump Control Module -J538-. Refer to the appropriate Wiring Diagram.
-- Delete DTC entries which were generated during testing using the Vehicle Diagnostic Tester.