Compression Pressure, Checking

WARNING: This page is about a different car, the 2015 Audi S7, 2015 Audi RS 7, 2014 Audi S7, 2014 Audi RS 7, and 2013 Audi S7. 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

Procedure

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 appropriate SYSTEM WIRING DIAGRAMS information.

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

-- Remove spark plugs with Spark Plug Removal Tool 3122B.

-- Check the compression using the Compression Tester Kit 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 Pressure
New	10.0 to 15.0
Wear limit	9.0
Maximum difference between cylinders	3.0

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

-- Install the spark plugs, refer to => 411.

-- 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 appropriate SYSTEM WIRING DIAGRAMS information.

-- If there are any faults stored in the DTC memory that occurring during testing, erase them see Vehicle Diagnostic Tester, Guided Functions , check DTC memory , then generate readiness code .