COMPRESSION, CHECKING Audi S5 I facelift

COMPRESSION, CHECKING

Special tools and workshop equipment required

1. Spark Plug Removal Tool 3122 B
2. Compression Tester V.A.G 1763
3. Ignition Coil Puller T40039

Scheme 206

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

Remove the rear noise insulation -2-. Refer to Description and Operation in Underbody Trim.

Disconnect the electrical connector -2- on the Engine Speed (RPM) sensor -G28-.

Scheme 207

Note. Ignore -1-.

Remove the air duct -arrows-.

Scheme 208

Free up the fuel line and the line to the EVAP canister on the air guide pipe.

Scheme 209

Disconnect the connector -1- from the Mass Airflow (MAF) sensor -G70-.

Disconnect the vacuum line -3- from the air guide pipe.

Lay aside air guide pipe with connected crankcase ventilation hose -2- by loosening hose clamp -4- and opening clips -arrows-.

Disconnect the vacuum line -1-.

Scheme 210

Remove the air filter housing and disconnect the electrical connector -2- on the rear side at the intake air switch-over valve -N335-.

Remove hose -3- from the secondary air system.

Disconnect the coolant hose -3- from the coolant overflow reservoir.

Scheme 211

Remove the bolts -arrows-.

Disconnect the electrical connector on the engine coolant lever warning switch -F66- and move the coolant overflow reservoir with the coolant hoses -1 and 2- still connected to the side.

Pull the oil dipstick -1- out of the guide tube.

Scheme 212

Remove the bolts -2 and 3-.

Disconnect the electrical connectors on the ignition coils.

Press the electrical wiring harness to the side.

Remove the bolts -1 and 2-.

Scheme 213

Disconnect the electrical connectors on the ignition coils.

Press the electrical wiring harness to the side.

Remove all the ignition coils with the T40039.

Scheme 214

Remove the spark plugs using the 3122 B.

Check compression pressure using the V.A.G 1763.

Note. Using tester, refer to 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 the procedure on each cylinder.

Assemble in reverse order of disassembling. Note the following

Install spark plugs.

Install the rear noise insulation. Refer to DESCRIPTION AND OPERATION in Underbody Trim.

There will be faults stored in the engine control module (ECM) Diagnostic Trouble Code (DTC) memory because the connectors were disconnected.

Generate readiness code in Guided Functions using the vehicle diagnostic tester.