Vauxhall Workshop Service and Repair Manuals

Spark Plug Thread, Recondition

Remove cylinder head.

See corresponding operation in this group.

If spark plug thread is damaged (torn out), it is possible to insert a thin threaded bushing.

To do this, use a commercially available Special Spark Plug Tap to ream and cut thread in one operation.

Threaded bushing A = 17 mm/0.67 in.

Screw threaded bushing onto spark plug and into re-cut spark plug seat.

Prescribed torque: 20 Nm/14.75 lbf. ft.

The chemically treated surface of the threaded bushing creates a firm connection between the bushing and the cylinder head when the engine warms up.