Compression Pressure, Checking

WARNING: This page is about a different car, the 2011 Audi Q7, 2010 Audi Q7, and 2009 Audi Q7. However, it is still accessible from the selected car via links, so may be relevant.

Special tools and workshop equipment required

Glow Plug Socket 3220
Compression Tester Kit VAG1763 with Compression Tester Kit - Adapter 8 VAG1763/8

Procedure

Fig 1: Identifying Engine Cover -Arrows-

Courtesy of AUDI OF AMERICA, LLC

Engine oil temperature approximately 80° C
Battery voltage at least 12.5 V.

-- Carefully pull the engine cover off the 4 bolts one after the other -arrows-.

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

Fig 2: Identifying Connector From Fuel Pressure Regulator Valve -1-

Courtesy of AUDI OF AMERICA, LLC

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

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

Fig 3: Identifying Socket 3320 To Remove Glow Plugs

Courtesy of AUDI OF AMERICA, LLC

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

Fig 4: Identifying Adapter V.A.G 1763/8 And Compression Tester V.A.G 1763

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	bar pressure
New	28 to 33
Wear limit	21
Maximum difference between cylinders	5

Assembling

Assemble in reverse order of disassembling. Note the following:

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

-- If the engine was started while the connectors were disconnected, faults will be stored in the engine control module: "check the DTC memory" in "OBD" Vehicle Diagnostic Tester.