Compression Pressure, Checking

WARNING: This page is about a different car, the 2012 Audi Q5, 2011 Audi Q5, 2010 Audi Q5, and 2009 Audi Q5. 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
Puller - Ignition Coil T40039

Procedure

Fig 1: Identifying Engine Covers

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Engine oil temperature: minimum 30 °C (86 °F)
Battery voltage minimum 12.5 V.

-- Remove the rear engine cover -top arrows-.

-- Remove the tower brace, refer to TOWER BRACE, REMOVING AND INSTALLING .

Fig 2: Identifying Strut Tower Brace, Bolts -1- And Nuts -2-

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-- Remove the bolts -arrows-.

Fig 3: Identifying Coolant Overflow Reservoir

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-- Disconnect the connector from the Engine Coolant Level Warning Switch -F66- and move the coolant reservoir to the side with the coolant hoses -1 and 2- still connected.

NOTE:

Be careful not to bend the coolant hose -2-.

-- Remove the bolts -arrows- and disconnect the electrical connectors to the ignition coils on the left cylinder head.

Fig 4: Identifying Screws From Ignition Coil Wiring Harness

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-- Press the electrical wiring harness down slightly.

-- Disconnect the connector -3- to the fuel injectors on the rear of the left cylinder head.

Fig 5: Cylinder Bank 2 Oxygen Sensor Electrical Connectors

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NOTE:

Ignore items -1, 2 and 4- and -arrows-.

-- Remove the air filter housing, refer to AIR FILTER HOUSING, REMOVING AND INSTALLING .

-- Remove the bolts -arrows- and disconnect the electrical connectors to the ignition coils on the right cylinder head.

Fig 6: Identifying Bolts On Right Cylinder Head

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-- Press the electrical wiring harness to the side.

-- Disconnect the connector -3- to the fuel injectors on the rear of the right cylinder head.

Fig 7: Identifying Bolts -Arrows- And Right Connector Bracket

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NOTE:

Ignore items -1, 2 and 4- and -arrows-.

-- Remove all the ignition coils using the Puller - Ignition Coil T40039.

Fig 8: Identifying Ignition Coil Puller T40039 Removing Ignition Coils

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-- Remove the 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 technician press the accelerator pedal down all the way while operating the starter until the pressure increase is no longer displayed on the tester.

Compression Pressure	Bar Pressure
New	14.5 to 21.0
Wear limit	14.0
Maximum difference between cylinders	3.0

Assembling

Tightening specifications, refer to OVERVIEW - CYLINDER HEAD .

Assemble in reverse order of disassembling. Note the following:

-- Install the spark plugs, refer to 6-CYLINDER 3.2 FSI GASOLINE ENGINE .

-- Install the air filter housing, refer to AIR FILTER HOUSING, REMOVING AND INSTALLING .

-- Install the tower brace, refer to TOWER BRACE, REMOVING AND INSTALLING .

-- If the engine was started while the electrical connectors were disconnected, then the following fault is stored in the engine control module: "generate readiness code" in "Guided Functions" Vehicle Diagnostic Tester.