Checking, removing and installing glow plugs (BMW 3 Series E46)

Verification conditions:

• The battery voltage is not less than 11.5 V.
• The glow plug fuse, located in the fuse box behind the glove compartment on the right, is OK. The location of the fuse box is shown in the Specifications to Chapter On-board electrical equipment.

Removal and inspection

1. Remove the intake manifold, refer to Section Removal and installation the intake manifold.

2. The glow plugs are located between the intake ports in the cylinder head. Disconnect the glow plug connector. To do this, squeeze the clamps on the plugs.

3. Connect the LED test lamp to the positive terminal of the battery (+) and apply it to each glow plug in sequence.

The diode lights up: The glow plug is working properly.

The diode does not light: The glow plug is faulty and must be replaced.

This requires a 12 mm key with a depth of 20 mm, for example, HAZET-4760-1.

4. Remove the glow plugs.

Installation

5. Screw in the glow plugs and tighten them to a torque of 20 Nm.

Do not exceed the specified tightening torque, otherwise the annular gap between the glow rod and the threaded part will increase. This will lead to premature failure of the spark plug.

6. Connect the electrical wires and secure them.

7. Install the inlet pipe, refer to Section Removal and installation the intake manifold.