Audi Workshop Service and Repair Manuals

Checking compression

Special tools and workshop equipment required

t	Removal lever -80-200-

t	Hose clamps for hoses up to 25 mm Ø -3094-

t	Spark plug socket and extension -3122 B-

t	Compression tester -V.A.G 1763-

Test conditions l  Engine oil temperature at least 30 °C. l  Battery voltage at least 12.5 V

Test sequence –  Remove engine cover panel -arrows-.

–  Remove cover -1- on left side of engine compartment.

–  Clamp off coolant hose -2- using hose clamp -3094- and detach coolant hose from coolant expansion tank. –  Unbolt coolant expansion tank -arrow-. –  Disconnect electrical wiring for coolant shortage indicator switch -F66- at coolant expansion tank (bottom). –  Tie coolant expansion tank to one side; coolant hoses -1- and -3- remain connected.

–  Remove cover -1- at right of engine compartment.

–  Remove bolts -arrows-. –  Disengage activated charcoal filter solenoid valve 1 -N80--item 1- at air duct. –  Remove air duct -2-.

–  Pry off retaining clips -2- for wiring harness at air cleaner housing (use removal lever -80-200-). –  Unplug electrical connector -1- at air mass meter -G70-. –  Remove air cleaner housing -arrows-.

–  Remove covers for cylinder head cover (left and right) -arrows-.

–  Pull off all six spark plug connectors -arrows-. –  Remove spark plugs with spark plug socket -3122 B-.

–  Detach electrical 5-pin connector -1- from ignition coil output stage -2-. –  Unplug electrical connectors at all injectors. –  Test the compression pressure with the compression tester -V.A.G 1763-.   Note Using the compression tester → operating instructions. –  Have a 2nd mechanic press down the accelerator pedal completely and simultaneously operate the starter until the pressure no longer increases on the tester display. Compression pressure:

New pressure in bar	Wear limit bar	Permissible difference between cylinders bar
9.0 … 14.0	7.5	3.0 (maximum)

Installation is carried out in the reverse order; note the following: –  Fill cooling system → Anchor. –  Interrogate and erase the fault memory for engine control unit after testing compression pressure, as faults are stored when the connectors are unplugged → Vehicle diagnosis, testing and information system VAS 5051. Tightening torque

Component	Nm
Spark plugs in cylinder head	30