Compression Pressure, Checking

WARNING: This page is about a different car, the 2016 Audi A7 Quattro. However, it is still accessible from the selected car via links, so may be relevant.

Special Tools And Workshop Equipment Required

Compression Tester Kit :VAG1763 with Oil Pressure Gauge Kit - Adapter 8 :VAG1763/8

Engine oil temperature at least 30 °C (86 °F).
Battery voltage at least 12.5 V.

-- Remove the engine cover. Refer to ENGINE COVER, REMOVING AND INSTALLING .

-- Disconnect the connectors on all of the glow plugs.

-- Disconnect the connector -arrow- on the Fuel Pressure Regulator Valve -N276- from the cylinder bank 1 (right) fuel rail.

Courtesy of AUDI OF AMERICA, LLC

-- In order to reduce the fuel pressure in the fuel rail, start the engine briefly.

-- Remove all the glow plugs. Refer to GLOW PLUG, REMOVING AND INSTALLING .

-- Install the :VAG1763/8 in place of the glow plugs and connect the :VAG1763 .

Courtesy of AUDI OF AMERICA, LLC

NOTE:

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

-- Have a second technician operate the starter until the test stops showing an increase in pressure.

-- Repeat procedure on each cylinder.

Compression Pressure	Vehicles With A Turbocharger
Compression Pressure	Pressure
New	28 to 33 bar (406 to 478 psi)
Wear limit	21 bar (305 psi)
Maximum difference between cylinders	5 bar (72.5 psi)

Assembling

Assemble in reverse order of disassembling. Note the following:

-- Install the glow plugs. Refer to GLOW PLUG, REMOVING AND INSTALLING .

-- There will be entries stored in the Engine Control Module (ECM) Diagnostic Trouble Code (DTC) memory if the engine was started while the connectors were disconnected: Check DTC Memory in OBD . Refer to Vehicle Diagnostic Tester.