Checking Oil Pressure

WARNING: This page is about a different car, the 2014 Porsche Cayenne, 2013 Porsche Cayenne, 2012 Porsche Cayenne, and 2011 Porsche Cayenne. However, it is still accessible from the selected car via links, so may be relevant.

WARNING: Toxic substances

Danger of poisoning or suffocation
Danger of burns to the eyes and skin
→ 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.

WARNING: Hot fluid

Danger of scalding
→ Let the fluid cool down.

→ Wear personal protective gear.

WARNING: Highly inflammable or explosive materials

Danger of fire or explosion
→ Avoid contact with hot parts or sources of ignition.

→ Use suction to remove ignitable vapours.

→ Attach warning sign in a clearly visible position.

→ Contain leaked media using non-flammable absorbent material and put it in a container designed for this purpose for disposal in accordance with local requirements.

→ Secure collection containers/vessels to prevent them from tipping over.

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.

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: Oil Pressure Sensor And Oil Pressure Measuring Point Components Location

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Oil pressure sensor and oil pressure measuring point

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
A	Direction of travel

Screw adapter for oil-pressure gauge -1- with sealing ring -2- into the measuring point. Carefully tighten to max. 10 Nm (7.5 ftlb.).

Courtesy of PORSCHE CARS NORTH AMERICA, INC.

Adapter in measuring point

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Adapter setup
Screw oil-pressure gauge -3- onto the adapter -2- . Counter screw torque using an open-ended wrench -1- .

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Oil-pressure gauge on adapter
Move oil-pressure gauge upwards into position. When doing this, make sure the hose is not touching any rotating components. > Oil-pressure gauge set down securely

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Oil-pressure gauge set down securely
Complete motor for taking measurements.
Check that there are no rotating components touching the measuring hose and that the pressure gauge is easy to read when positioned.

Courtesy of PORSCHE CARS NORTH AMERICA, INC.

Oil-pressure gauge set down securely
Connect the PIWIS Tester. Connect battery charger.
- 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.
- The pressure readings can be shown graphically in the data logger.
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).