Audi Workshop Service and Repair Manuals

Checking compression Special tools and workshop equipment required

t  U/J extension and socket, 10 mm -3220-

t  Adapter -V.A.G 1381/12-

t  Compression tester -V.A.G 1763-

Procedure l  Engine oil temperature min. 30 °C l  Battery voltage at least 12.5 V –  Remove bonnet → Chapter. –  If fitted, unclip bracket -1-. –  Take off engine cover panel -arrows-. –  Remove noise insulation underneath (detach crankcase breather hose).

–  Unplug electrical connectors -2- on glow plugs. –  Pull retaining tab and loosen knurled nut -3- at main connector for unit injectors.   Note Ignore other -items-.

–  Unscrew all glow plugs using jointed spanner -3220-. –  Screw in adapter -V.A.G 1381/12- in place of the glow plug in each cylinder. –  Test the compression pressure with the compression tester -V.A.G 1763-.   Note Using the compression tester → Operating instructions. –  Have a 2nd mechanic operate starter until tester shows no further pressure increase.

Compression pressure	bar
When new	25.0 … 31.0
Wear limit	19.0
Difference between cylinders	5.0 (maximum)

Assembly is carried out in the reverse order; note the following: –  Install glow plugs → Rep. Gr.28. –  Interrogate and erase the fault memory for engine control unit, as faults are stored when the electrical connectors are unplugged → Vehicle diagnosis, testing and information system VAS 5051. Tightening torque

Component	Nm
Engine cover panel to bracket	5.5