Checking Oil Pressure

→ Ventilate the work area well.

→ Never ingest or inhale.

→ Read specific information on the Hazard Sheet.

→ Wear personal protective gear.

→ Do not smoke, eat or drink in the work area.

→ Let the fluid cool down.

→ Wear personal protective gear.

→ Avoid contact with hot parts or sources of ignition.

→ Use suction to remove ignitable vapours.

→ Attach warning sign in a clearly visible position.

Information 

The oil pressure may be too low for a number of reasons: 

• Oil is diluted (e.g. fuel gets into the oil due to too many cold starts without warming up the engine afterwards). 
• Oil pump is faulty. 
• Too much bearing clearance (e.g. crankshaft bearing). 
• Oil level is too low. 
• Oil pressure regulating valve is faulty. 
• Oil pressure sensor is faulty. 
• Incorrect oil has been used. Use only oil that has been approved by Porsche for the measurement. 

Information 

The oil pressure may be too high for a number of reasons: 

• Oil has thickened or is very cold after a cold start and high engine speeds. 
• Oil pump is faulty. 
• Mechanical oil pump pressure relief valve is faulty (oil pump needs to be replaced). 
• Oil pressure regulating valve is faulty. 
• Cable plug of oil pressure regulating valve has fallen off or open circuit between it and the control unit (oil pressure may be up to 11 bar, engine loses approximately 10 kW of engine power) 
• Oil pressure sensor is faulty. 
• Incorrect oil has been used. Use only oil that has been approved by Porsche for the measurement. 

1. Remove screw plug at the measuring point -5-  . When doing so, make sure that the sealing ring -6-  does not fall off. Soak up emerging engine oil with a cloth.
   Fig 1: Identifying Oil Pressure Sensor And Oil Pressure Measuring Point

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.
   1. Oil pressure sensor adapter
   2. O-ring
   3. Oil pressure sensor with integrated temperature sensor
   4. Screw, M6 x 40
   5. Stopper; test connection
   6. Sealing ring
   1. Direction of travel
2. Screw adapter for oil-pressure gauge -1-  with sealing ring -2-  into the measuring point. Carefully tighten to max. 10 Nm (7.5 ft lbs.).
   Fig 2: Identifying Measuring Point Adapter

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.
   Fig 3: Identifying Adapter Setup

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.
3. Screw oil-pressure gauge -3-  onto the adapter -2-  . Counter screw torque using an open-ended wrench -1-  .
   Fig 4: Identifying Oil-Pressure Gauge On Adapter

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.
4. Move oil-pressure gauge upwards into position. When doing this, make sure the hose is not touching any rotating components.
   Fig 5: Securing Oil-Pressure Gauge

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.
5. Fit deflection roller, oil dipstick with guide tube, drive belt and intake pipe for the measurement.
6. Check that there are no rotating components touching the measuring hose and that the pressure gauge is easy to read when positioned.
   Fig 6: Securing Oil-Pressure Gauge

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.
7. Connect the PIWIS Tester. Connect battery charger.
   • Read out DME fault memory and correct faults.
   • Use the PIWIS Tester to call up the actual values for oil pressure, engine temperature and engine speed in DME. The oil pressure displayed in the PIWIS Tester is always higher than that on the pressure gauge by the value of the ambient pressure (depending on the altitude, e.g. 1000 hPa).
   • The pressure display on the oil-pressure gauge must be the same as the value on the PIWIS Tester once adjusted by the ambient pressure value.
   • The pressure display on the oil-pressure gauge is much slower than that on the PIWIS Tester. The measured value on the PIWIS Tester fluctuates rapidly. The trend between the two measuring instruments is significant.
   • The measured oil pressure remains virtually constant over different rev ranges. The measurement using the oil-pressure gauge merely confirms that the oil pressure sensor's display is correct.
   • A control loop measurement of the variable oil pump system is checked using the "Short test" in the PIWIS Tester.
8. Start the engine and let it run until it reaches the measurement temperature. → Engine temperature: 90°C 

   Measured values (examples)

   • For a cold start (e.g. 24 °C), pressure immediately jumps to 8 bar briefly (oil-pressure gauge).
   • Following cold start, oil pressure drops briefly to 3 bar (oil-pressure gauge) - 4000 hPa (PIWIS Tester).
   • For warm-up phase at idle speed, pressure drops from 3 bar to 1.8 bar (oil-pressure gauge) - 4000 hPa drops to 2800 hPa (PIWIS Tester).
   • At engine temperature of 90 °C at idle speed, 1.5 bar to 1.6 bar (oil-pressure gauge) - 2600 hPa (PIWIS Tester).
   • At engine temperature of 90 °C at 1000 rpm, 2.8 bar (oil-pressure gauge) - 3800 hPa (PIWIS Tester).
   • At engine temperature of 90 °C at between 2000 rpm and 4000 rpm, the oil pressure is almost constant at 3.0 bar (oil-pressure gauge) - 4000 hPa (PIWIS Tester). The value may fluctuate by 0.1 bar (100 hPa).