BMW 3-Series and Z3 Models Repair and Service Manual 1992-1998

SIX-CYLINDER MODELS (Refer to illustrations 4.20 and 4.22)

REMOVAL

17. Two knock sensors are fitted, screwed into the left-hand side of the cylinder block. One sensor detects knocking in No. 1 to 3 cylinders, and the other sensor detects knocking in No. 4 to 6 cylinders.



18. Disconnect the battery negative lead. Caution: If the radio in your vehicle is equipped with an anti-theft system, make sure you have the correct activation code before disconnecting the battery.



19. Remove the intake manifold (see Chapter 4B).



20. Locate the sensor connector bracket which is located beneath the idle speed control valve (see illustration). Warning: If both knock sensors are to be removed, mark the wiring connectors to ensure correct installation. Incorrect reconnection may result in engine damage.



21. Disconnect the sensor wiring connector(s).



22. Unscrew the securing bolt and remove the know sensor, noting the routing of the wiring. The sensor for cylinders 1 to 3 is located beneath the temperature sensors in the cylinder head (see illustration). The sensor for cylinders 4 to 6 is located to the rear of the sensor wiring connector bracket.


INSTALLATION


23. Commence installation by thoroughly cleaning the mating faces of the sensor and the cylinder block.



24. Install the sensor to the cylinder block, tightening the securing bolt to the specified torque.



25. Route the wiring as noted before removal, and then reconnect the connector(s) to the bracket, ensuring that the connectors are positioned as noted before removal. Warning: Ensure that the wiring connectors are correctly connected as noted before removal. If the connectors are incorrectly connected (i.e., mixed up), engine damage may result.



26. Install the intake manifold (see Chapter 4B).

3-SERIES MODELS

HEADLIGHT (Refer to illustrations 5.2, 5.3, 5.4a and 5.4b)

1. Release the retaining clip and remove the relevant access cover from the rear of the headlight unit (see illustration). To improve access to the left-hand headlight, remove the air cleaner housing (see Chapter 4).



2. Disconnect the wiring connector from the rear of the bulb (see illustration).



3. Unhook and release the ends of the bulb retaining clip and release it from the rear of the light unit. Withdraw the bulb (see illustrations).



4. When handling the new bulb, use a tissue or clean cloth to avoid touching the glass with the fingers; moisture and grease from the skin can cause blackening and rapid failure of this type of bulb. If the glass is accidently touched, wipe it clean using isopropyl alcohol.



5. Install the new bulb, ensuring that its locating tabs are correctly located in the light cutouts, and secure it in position with the retaining clip.



6. Reconnect the wiring connector and install the access cover, making sure it is securely reinstalled.


FRONT SIDELIGHT (Refer to illustration 5.9)


7. Depress the retaining clip and remove the access cover from the rear of the headlight unit.



8. Withdraw the sidelight bulb holder from the headlight unit (see illustration). The bulb is of the capless type and is a push fit in the holder.



9. Installation is the reverse of the removal procedure making sure the access cover is securely reinstalled.

• Introduction: Vehicle identification numbers. Buying parts. Safety. Maintenance techniques. Chemical and lubricants, and more.
• Tune-up and routine maintenance
• Four-cylinder engines
• Six-cylinder engines
• General engine overhaul procedures
• Cooling, heating and air-conditioning systems
• Fuel and exhaust systems
• Engine electrical systems
• Emissions control systems
• Manual transmission
• Automatic transmission
• Clutch and driveline
• Brakes
• Suspension and steering systems
• Body
• Chassis electrical system
• Wiring diagrams