Late model cars
Removal
Turn off the ignition. Pry up the mounting bolt covers and unscrew the two bolts located under the covers.
Remove the oil filler cap and cylinder head cover.
Remove the plugs from each of the coils by pulling the metal clips on the plugs upward.
Remove the two mounting bolts on each ignition coil and remove the coils.
Note: On cylinders 1 and 6, pay attention to the ground busbars on the valve cover. On a metal valve cover, pay attention to the ground busbar from the wiring harness between cylinders 2 and 3. On a plastic valve cover, pay attention to the ground wire on the junction box. When installing the wires, install them in the same position.
Examination
1 - contact 15;
2 - contact 4;
3 — contact 1.
The figure shows the plug of one of the ignition coils.
Connect an ohmmeter between terminals 1 and 15 and measure the resistance of the primary winding. It should be about 0.8 ohms.
Note: Secondary winding resistance (between spark plug contact, terminal 4 and ground) not measured.
Replace the spark plug plug.
Installation
Install the ignition coils with spark plug connectors and secure with bolts together with the ground busbars.
Place the plug onto the ignition coil and secure it with a metal clip.
Install the valve cover trim (housing) and oil filler cap.
(The article was copied from an online resource BMWMAN)