Volkswagen Workshop Service and Repair Manuals > Golf Mk4 > Power unit | 4-cylinder diesel engine with unit injector | Engine cylinder head, valve gear | Assembly overview - cylinder head

Checking compression

Special tools and workshop equipment required

t	Jointed wrench 10 mm -3220-

t	Torque wrench -V.A.G 1331-

t	Adapter -V.A.G 1381/12-

t	Compression tester -V.A.G 1763-

Test prerequisite

l	Engine oil temperature at least 30 °C

Test procedure

–	Pull off central connector for unit injectors.

–	Remove all glow plugs using 10 mm jointed wrench -3220-.

–	Screw in adapter -V.A.G 1381/12- in place of glow plugs.

–	Check compression using compression tester -V.A.G 1763-.

Note

Using the compression tester ⇒Operating instructions

–	Operate starter until tester shows no further pressure increase.

Compression pressures:

New: 25…31 bar, wear limit: 19 bar

Maximum permissible difference between all cylinders: 5 bar

–	Install glow plugs using 10 mm jointed spanner -3220-, specified torque: 15 Nm.

–	Reading fault memory → Chapter; reading and clearing fault memory of engine control unit.

Note

Disconnecting the central connector for unit injectors causes faults to be stored. Therefore read and clear fault memory.

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