1. Disconnect the negative cable from the battery.
2. On models with an M67 cy engine, a decorative engine cover; on other models, remove the intake manifold (see Engine).
3. On models with an M51 engine, loosen the nut and disconnect the wire.
4. On models with an engine other than M51, squeeze the clamps of the electrical wiring connector and disconnect it.
5. Turn out glow plugs by means of the special adaptation.