Ignition coils — removal and installation (BMW 3 Series E46)

4-cylinder engine M43TU

Removal

1. Each spark plug is equipped with a separate ignition coil. All coils are connected into a common module, which is located above the upper support of the right front suspension (Fig. 3.1).



2. Turn off the ignition.

3. Disconnect the electrical connector from the ignition coil module.

4. Unfasten the latches and remove the plastic screen from the ignition coil module. Disconnect the high-voltage wires from the module (fig. 3.4,a,b). Mark the wires to avoid confusion during installation. The cylinder numbers for connecting the corresponding wires are marked on the top of the module coils.





5. Loosen the coil module mounting bolts and remove the module from the body.

Installation

6. Installation is performed in reverse order. Do not mix up the high-voltage wires when connecting them to the module.

4-cylinder engine N42

Removal

7. Remove the two bolts securing the cover above the engine, lift the front edge of the cover and pull it forward.

8. At the rear of the engine compartment, turn the two fasteners 90° counterclockwise and remove the cabin filter cover. Pull the filter out of the housing.

9. Unfasten the four fasteners of the box for laying the wires and remove the sleeves with wires from the box (Fig. 3.9).



10. Unscrew the four screws and pull the cabin filter housing forward (Fig. 3.10).



11. Unscrew the oil filler cap. Align the marks on the opening neck and on the neck (Fig. 3.11). Squeeze the unmarked sides of the neck and pull it out of the neck.





12. Remove the plastic cover from the ignition coil module (Fig. 3.12).



13. Open the coil electrical connector latches and disconnect the coil connector plugs (Fig. 3.13). Remove the coils from the spark plugs.

Installation

14. Installation is performed in the reverse order of removal. The protrusion on the cylinder head must enter the rubber seal on the underside of the coil.

6-cylinder engines

Removal

15. Each spark plug has its own coil. The coils are located directly above the spark plugs in the cylinder head cover.

16. Turn off the ignition.

17. Unscrew the oil filler cap.

18. Remove the air duct for the ventilation and heating system from the rear of the engine compartment as follows.

• a) Remove the cabin filter cover by turning its latches 90° counterclockwise. Pull the filter out of the housing.
• b) Unfasten the four fasteners of the box for laying the wires and remove the sleeves with wires from the box (Fig. 3.9).
• c) Remove the four screws and pull the cabin filter housing forward.
• d) In the left rear corner of the engine compartment, pull off the seal, turn the two fasteners counterclockwise and move the trim panel forward a little
• d) Remove the two screws and remove the air duct.

19. Remove the plugs from the plastic cover above the injectors, unscrew the screws and remove the cover (Fig. 3.19).



20. Remove the plastic cover from the cylinder head cover. To remove the outer cover, remove the plugs, unscrew the two nuts, lift the cover and slide it forward (Fig. 3.20).





21. Lift the coil connector lock and disconnect the connector plug from the coil (Fig. 3.21). If all coils need to be removed, disconnect the connectors of all coils and disconnect the ground busbar on the front side of the timing chain cover. The wiring harness can now be released from the fasteners and moved to the side.



22. Remove the two coil mounting nuts. Note the ground wires and brackets that are secured with the same nuts. If the bracket is secured with nuts from two different coils, you may need to remove the nut from the adjacent coil and remove the bracket so that it does not interfere with the removal of the desired coil (Fig. 3.22). Keep in mind that the coils are spring-loaded and will rise as the nuts are removed.





23. Remove the coil from the spark plug and from the cylinder head cover (Fig. 3.23).

Installation

24. Installation is performed in reverse order. Do not forget to secure all the brackets and ground wires that were before disassembly with the coil nuts

(This article is based on information from the website «www.bmwman.ru»)