Removal and installation injectors (BMW 3 Series E46)

Damaged injectors can cause strong shocks during engine operation, reminiscent of an engine with damaged bearings. If such phenomena occur, start the engine at idle speed and loosen the union nuts of the high-pressure pipes one by one. If the shocks disappear when unscrewing any nut, this indicates a defect in the corresponding injector. The injector is checked using a pressure gauge (work of the service station).

The first signs of a faulty injector are as follows:

• Engine power loss;
• Excessively black exhaust gases;
• Thick blue smoke on cold start;
• High fuel consumption;
• Engine overheating;
• Knocking in one or more cylinders;
• Incomplete combustion.

Removal

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

2. Clean the high pressure fuel lines with cold cleaner.



3. Remove the high-pressure fuel lines. To do this, use a spanner, such as HAZET 4550, to unscrew the union nuts on the injectors and the high-pressure fuel pump.

4. Cover the holes with protective caps or film with rubber bands to prevent dirt from getting into them.

5. Disconnect the cable going to the fourth cylinder injector.





6. Disconnect the drain hoses between the nozzles using pliers.

7. Disconnect the clamps securing the injectors "2" and remove the injectors.

If the nozzle is not removed, you can use an impact puller. To use it, you need to make a special tool that is screwed onto the nozzle.

The tool can be made as follows. Cut off the old nozzle at a distance of about 5 cm behind the union nut. Solder the M6 nut to the cut end of the pipeline with hard solder.

8. Screw the tool onto the injector and attach the impact puller to the soldered nut. Pull out the injector.

9. Remove the heat shield.

Installation

10. Be sure to install a new heat shield gasket between the cylinder head and the injector.

11. Insert the nozzle.

The injector with the needle displacement sensor is always inserted into the fourth, i.e. rear cylinder. It can be recognized by the attached cable.

12. Connect the cable of the fourth injector.

13. Install the clamping clamps on the injectors. Tighten the clamping nuts to a torque of 10 N·m.

14. Install new drain hoses between the injectors.

15. Secure the high-pressure fuel lines to the injectors and high-pressure fuel pump with a torque of 25 N·m.



16. Install the intake manifold, refer to Section Removal and installation the intake manifold.