Audi Workshop Service and Repair Manuals

Checking compression

Special tools and workshop equipment required

t	Spark plug socket and extension -3122 B-

t	Compression tester -V.A.G 1763-

t	Puller -T40039-

Procedure l  Engine oil temperature at least 30 °C. l  Battery voltage at least 12.5 V –  Switch off ignition. –  Pull off engine cover panel (rear) -arrows-.

–  Pull off engine cover panel (front) -arrows-.

–  Unbolt coolant expansion tank -arrow-. –  Unplug electrical connector for coolant shortage indicator switch -F66- at bottom of expansion tank and move expansion tank to one side with coolant hoses -1- and -2- attached.

–  Pull non-return valve -1- off connection at air intake hose. –  Remove air intake hose. To do so, release hose clip -2- and clamps -arrows-.

–  Remove bolts -arrows-. –  Remove air ducts -1- and -2-.

–  Unscrew bolts -arrows- and unplug electrical connectors at ignition coils on cylinder head (left-side).   Note Disregard -items 1 ... 4-.

–  Unscrew bolts -arrows- and unplug electrical connectors at ignition coils on cylinder head (right-side).   Note Disregard -items 1 ... 5-.

–  Pull ignition coils out with puller -T40039-.

–  Unplug electrical connector -3- leading to injectors at rear of cylinder head (left-side).   Note Disregard items marked -1-, -2- and -arrow-.

–  Unplug electrical connector -1- leading to injectors at rear of cylinder head (right-side).   Note Ignore -arrow-. –  Remove spark plugs with spark plug socket -3122 B-. –  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	bar
When new	11.0 … 14.0
Wear limit	10.0
Difference between cylinders	3.0 (maximum)

Assembly is carried out in the reverse order; note the following: –  Install spark plugs → Booklet803 or → Booklet805. –  Finally, interrogate fault memory and erase if necessary. If you have erased the fault memory, you must then generate the readiness code in the engine control unit via “Guided fault finding” mode → Vehicle diagnosis, testing and information system VAS 5051. Tightening torque

Component	Nm
Hose clips (9 mm wide)	3