Warm up the engine (in motion), so that the oil temperature is about 80°C.
The oil pressure indicator light switch is located on the oil filter housing. Loosen the bolt (2) and remove the oil filter cover to allow the oil to drain into the engine. There is also another design of oil filter with a screw cap.
Disconnect the wire from the oil pressure warning light switch and unscrew the switch (12).
Screw in a suitable pressure gauge in place of the oil pressure indicator light switch.
Install the oil filter cover and secure it with the bolt.
Start the engine and let it idle. On all engines, the oil pressure must be at least 0.5 bar (kgf/cm²).
Accelerate the engine to 5000-6000 rpm, the oil pressure should now be from 4.0 bar (diesel - 3.8 bar) to 4.7 bar.
Install the oil pressure warning light switch with a new sealing ring and tighten it to 20 Nm; connect the wire. Tighten the cover fasteners to the oil filter housing with a torque of 20 Nm.
If the oil pressure differs greatly from the specified values, then you need to refer to the troubleshooting section.
Original publication posted on the website BMWMAN.RU