The oil pressure indicator is controlled electrically by a pressure sensor, the pressure sensor is screwed into the top of the oil filter or into the bottom on 8-cylinder engines. At operating temperature, the oil pressure should decrease by 0.5 bar at idle. When applying "gas" the pressure must increase again and reach at least 3 bar at 3,000 rpm. The oil pressure reducing valve is built into the pump cover. 6-cylinder engines have another oil pressure relief valve (5 bar) installed in the front oil channel of the front wall.
Oil line with oil cooler for engines 280 (280S and 280SE)
1. Oil pump. 2. Oil pressure reducing valve 8 bar. 3. Oil filter. 4. Excess flow valve - filter element 3.5 bar. 5. Thermostat. 6. Oil cooler. 7. Oil pump drive. 8. Shaft of the intermediate sprocket. 9. Distributor drive. 10. Shaft of the intermediate sprocket. 11. End sprocket. 12, 13. Camshaft. 14. Chain tensioner. 15. Rocker. 16. Camshaft bearing