Oil pressure and level sensors — removal and installation (BMW 3 Series E46)

Engine M43TU

Oil pressure alarm sensor

1. Unscrew the oil filter cap and allow the oil from the filter to drain into the pan. This will reduce oil loss when unscrewing the sensor.

2. Remove the generator (see chapter 5A) and its support bracket, then disconnect the sensor electrical connector and unscrew the sensor from the base of the oil filter housing (Fig. 22.2).



3. Screw in the new sensor and tighten it to the specified torque.

4. Connect the sensor connector. Install the generator with the bracket and the oil filter cover. Check the oil level (see Weekly Checks).

Oil level alarm sensor

5. Drain the engine oil as described in Chapter 1.

6. Remove the crankcase guard from under the engine.

7. Disconnect the electrical connector of the sensor, unscrew the three nuts and remove the oil level sensor (Fig. 22.7).



8. Clean the mating surfaces of the pan and sensor.



9. Put a new seal on the sensor, apply a compound to the threads of the sensor studs to prevent unscrewing, screw on the nuts and tighten them securely.

10. Install the engine guard under the engine and fill the engine with oil.

Engine N42

Oil pressure alarm sensor

11. The oil pressure switch is located on the left side of the engine, behind the alternator. Remove the alternator as described in Chapter 5A.

12. Disconnect the electrical connector from the sensor and unscrew the cylinder block sensors (fig. 22.12). Prepare for an oil leak.



13. Install the sensor in the reverse order. Replace the sealing washer under the sensor. Tighten the sensor to the required torque.

Oil level alarm sensor

14. The procedure for removing and installing this sensor is similar to that described in 8 pp. 5-10 for the M43TU engine.