Checking compression

Special tools and workshop equipment required

• Spark plug socket - 3122 B-
• Torque wrench (5 … 50 Nm) - V.A.G 1331-
• Compression tester - V.A.G 1763-
• Tapered roller bearing puller - T10094-

Prerequisites for check

• The engine oil temperature must be at least 30 °C.

Sequence of operations

• Pull 4-pin connectors off ignition coils.
• Remove ignition coils. Use puller -T10094- for this purpose.
• Remove wiring guide from camshaft housing.

• Remove spark plugs using spark plug socket 3122 B.
• Remove fuse for injection valves from fuse holder. Fuse assignment ⇒ Current flow diagrams, Electrical fault finding and Fitting locations
• Check compression using compression tester - V.A.G 1763-.

• Operate starter until tester shows no further pressure increase.

Compression pressures:

New: 10 … 15 bar

Wear limit: 7 bar

Permissible difference between all cylinders: 3 bar

• Insert spark plugs using spark plug socket and extension - 3122 B- and tighten to 30 Nm.

Further assembly is basically a reverse of the dismantling sequence.

• Read fault memory, rectify any faults and then erase fault memory: ⇒ Vehicle diagnostic tester “Guided fault finding”.
• The readiness code must be generated if the fault memory has been erased.