Cylinder Head Cover — Removal and Installation (BMW 3 Series E46)

Note: New seals and gasket may be required during installation - see text.

Removal

1. To provide sufficient space, remove the air intake duct for the interior ventilation at the rear of the engine compartment (fig. 4.1 a, b):

• 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 cable management box and remove the sleeves with wires from the box.
• 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 slightly.
• d) Remove the two screws and remove the air duct.

2. Unscrew and remove the engine oil filler cap.



3. Remove the plastic cover from the fuel rail and from above the cylinder head cover. To remove the covers, pull out the plugs and unscrew the nuts that secure them. To remove the cover from the cylinder head, lift it, slide it forward and remove it through the oil filler neck (fig. 4.3 a, b).





4. Loosen the bolt and disconnect the ground busbar from the cylinder head cover near the spark plug hole of cylinder No.1. Also disconnect the ground wires in the middle and at the rear of the cylinder head cover (fig. 4.4 a, b).





5. Disconnect the electrical connectors from the ignition coils (Fig. 4.5).





6. Disconnect the wiring from the cylinder head cover and move it to the side.

7. Unscrew the ignition coil mounting nuts and carefully remove the coils from the spark plugs (Fig. 4.7).



8. Disconnect the crankcase ventilation hose from the side of the cylinder head cover (Fig. 4.8).



9. On the right side of the cylinder head cover, disconnect the oxygen sensor electrical connectors and move the wiring to the side.



10. Loosen the nuts and bolts of the cylinder head cover (including in the center of the lid) and remove it from the engine. Remember the position of the washers, seals and gaskets. Remove them. if they do not hold well.

Installation

11. First, check the condition of all seals and gaskets. Replace any that are faulty.

12. Clean the mating surfaces of the cover and cylinder head. Apply Drei Bond 1209 sealant where the valve timing adjusters contact the cylinder head and to the corners of the semi-circular cutouts on the back of the cylinder head (fig. 4.12, a-c). Place the outer and inner gaskets on the cylinder head cover.







13. Place the cover on the cylinder head, being careful not to dislodge the gaskets. Make sure that the tabs on the back of the outer gasket fit into the cutouts in the cylinder head.



14. Secure the cover with nuts and bolts, making sure that the seals are in their original places, then gradually tighten the fasteners to the required torque.

15. The rest of the installation is carried out in the reverse order of removal, taking into account the following notes.

• a) Secure the ground wires in their original places.
• b) Tighten the ignition coil mounting bolts and nuts to the specified torque.
• c) When connecting high voltage wires to the coils, make sure that the rubber seals are in place.

[The original article is posted on the resource BMWman]