Compression Pressure, Checking

WARNING: This page is about a different car, the 2016 Audi Q5, 2015 Audi Q5, and 2014 Audi Q5. 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 VAG1763/14

Procedure

Engine oil temperature approximately 80 °C (176 °F)
Battery voltage minimum 12.5 V.

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

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

Fig 1: Fuel Pressure Regulator Valve -N276-

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 Compression Tester Kit - Adapter 8 VAG1763/8 in place of the glow plugs and connect the Compression Tester Kit VAG1763.

Fig 2: Identifying Compression Tester Kit - Adapter

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.	Vehicles with Two Turbochargers.
Compression Pressure	Bar Pressure
New	28 to 33	26 to 31
Wear limit	21	20
Maximum difference between cylinders	5	5

Assembling

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

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

-- Install the engine cover, refer to ENGINE COVER, REMOVING AND INSTALLING .

-- If there are any faults stored in the Diagnostic Trouble Code (DTC) memory that occurring during testing, erase them on the Vehicle Diagnostic Tester, Guided Functions , Check DTC Memory .