Compression, Checking

WARNING: This page is about a different car, the 2018 Audi A6 Quattro, 2017 Audi A6 Quattro, and 2016 Audi A6 Quattro. 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 at least 30 °C (86 °F).
Battery voltage at least 12.5 V.

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

-- Disconnect the left and right connectors -4 and 5- on the back of the cylinder head to the fuel injectors.

Courtesy of AUDI OF AMERICA, LLC

NOTE:

Ignore -1, 2 and 3-.

-- Remove the spark plugs with :3122B .

-- Check the compression using the :VAG1763 .

NOTE:

Information on using the tester. Refer to the Operating Instructions.

-- Have a second technician 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	11.0 to 14.0 (159.54 to 203.05 psi)
Wear limit	10.0 (145.03 psi)
Maximum difference between cylinders	3.0 (43.5 psi)

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 .

-- Erase Diagnostic Trouble Code (DTC) entries which have occurred during the testing:

The Vehicle Diagnostic Tester is connected.

-- Select the mode.

-- Press the Go to button and select the "Function/component selection" and the following tree structures one after the other:

Drive
01 - On Board Diagnostic (OBD) capable systems
Simos Fuel Injection and Ignition
Functions
Readiness code