Warm up the car engine to an oil temperature of approximately +80°C.
The hydraulic switch of the oil pressure drop indicator is located in the oil filter housing. Loosen the bolt "2" and remove the oil filter cover so that the oil flows into the engine. An alternative design is also available oil filter with screw cap.
Disconnect the electrical wire from the hydraulic switch and unscrew the hydraulic switch "12".
Screw in a suitable pressure gauge instead of the hydraulic switch.
Replace the filter cover.
Start the engine and let it idle. The oil pressure for all engines must be at least 0.5 bar.
Increase the crankshaft speed to 5000-6000 rpm. The oil pressure should be from 4.0 bar (for diesel engines from 3.8 bar) up to 4.7 bar.
Install the hydraulic switch with a new sealing gasket and tighten it to 20 Nm. Connect the electrical cable to the switch.
Tighten the oil filter cover fastening to 20 Nm.
If the oil pressure does not correspond to the specified values, see chapter "Diagnosing oil circulation problems".