Compression, Checking

WARNING: This page is about a different car, the 2018 Audi S6, 2017 Audi S6, and 2016 Audi S6. However, it is still accessible from the selected car via links, so may be relevant.

Special tools and workshop equipment required

Spark Plug Removal Tool :3122B
Compression Tester Kit :VAG1763

Engine oil temperature: minimum 30 °C (86 °F)
Battery voltage minimum 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 WITH POWER OUTPUT STAGES, REMOVING AND INSTALLING .

-- Remove spark plugs with :3122B .

-- Check the compression using the :VAG1763 .

NOTE:

For information on using the tester. Refer to the Operating Instructions.

-- Have a second mechanic press the accelerator pedal down all the way while operating the starter until the pressure increase is no longer displayed on the tester.

-- Repeat procedure on each cylinder.

Compression pressure	Bar (PSI) Pressure
	Engine Codes CEUC/CEUD/CTGE	Engine codes CRDB/CWUB/CWUC
New	10.0 (145) to 15.0 (217)	9.0 (130) to 14.0 (203)
Wear limit	9.0 (130)	8.0 (116)
Maximum difference between cylinders	3.0 (43)	3.0 (43)

Assembly is performed in the reverse order of disassembly, noting the following:

-- Install the spark plugs.

-- Install the ignition coils. Refer to IGNITION COILS WITH POWER OUTPUT STAGES, REMOVING AND INSTALLING .

-- Install the fuse for the Fuel Pump Control Module -J538-. Refer to the Appropriate Wiring Diagram.

-- If there are any faults stored in the DTC memory that occurring during testing, erase them see Vehicle Diagnostic Tester.