Initial Inspection and Diagnostic Overview
Checking oil pressure - checking operation of variable oil pump
Information
Information regarding function test on variable oil pump
Information
The PIWIS Tester, version 19.000 and later versions, can be used to call up a short test for the variable oil pump. If the short test is not displayed in the PIWIS Tester, a software update for the DFI control unit must be performed.
If an oil-pressure gauge needs to be connected for further tests, proceed according to the instructions starting from "Preliminary work".
1. Perform "Variable oil pump" short test in DME. The short test is active when the oil temperature is 60 degrees C. or higher.
1.1. Start the engine.
1.2. Call up "Variable oil pump" short test in DME.
1.3. Press and hold the accelerator and brake pedals simultaneously as instructed. The short test is performed and the message OK or not OK is then displayed.
Preliminary work
1. Remove Y-pipe or intake pipes upstream of the throttle valve to create unrestricted access to the drive belt and to the oil pressure sensor.
2. Remove drive belt in the area of the lower deflection roller.
3. Remove oil dipstick with guide tube. -1, 2, 3 and 11- Soak up emerging engine oil with a cloth.
Oil guide housing with accessories
1 - Guide tube
2 - O-ring
3 - Screw, M6 x 16
4 - Oil dipstick
5 - O-ring
6 - Screw, M6 x 25; timing-case cover to oil guide housing
7 - Oil level sensor
8 - O-ring
9 - Joint flange
10 - Screw, M6 x 20
11 - Screw, M6 x 16
A - Direction of travel
4. Remove deflection roller between the vibration balancer and generator. To do this, use a small screwdriver to pry off the lid and loosen the screw. Remove deflection roller with screw. -1-
Belt drive
1 - Deflection roller
2 - Hydraulic belt tensioner; tensioner to lever
3 - Screw, M8 x 96; complete lever to timing-case cover and cylinder head
4 - Deflection roller
5 - Dual poly-V-belt
Tools and materials
Tools
Oil pressure tester
1 - Oil pressure tester V.A.G. 1342 WE 1068
2 - Sealing ring
3 - Adapter
Checking oil pressure
Warning
Toxic substances
Danger of poisoning or suffocation
- Ventilate the work area well.
- Never ingest or inhale.
- Read specific information on the Hazard Sheet.
- Wear personal protective gear.
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 vapors.
- 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.
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
2. Screw adapter for oil-pressure gauge -1- with sealing ring -2- into the measuring point. Carefully tighten to max. 10 Nm (7.5 ftlb.)
Adapter in measuring point
Adapter setup
3. Screw oil-pressure gauge -3- onto the adapter -2-. Counter screw torque using an open-ended wrench -1-.
Oil-pressure gauge on adapter
4. 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
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.
Oil-pressure gauge set down securely
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 degrees C
Measured values (examples)
For a cold start (e.g. 24 degrees 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 degrees C). at idle speed, 1.5 bar to 1.6 bar (oil-pressure gauge) - 2600 hPa (PIWIS Tester).
At engine temperature of 90 degrees C). at 1000 rpm, 2.8 bar (oil-pressure gauge) - 3800 hPa (PIWIS Tester).
At engine temperature of 90 degrees 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).
Subsequent work
1. Remove oil-pressure gauge and adapter again.
2. Refit screw plug with new sealing ring. - Tightening torque: 15 Nm (11 ftlb.)
3. Fit deflection roller between the vibration balancer and generator. Tighten the screw. Press on lid. -1-
Belt drive
1 - Deflection roller - Tightening torque: 32 Nm (24 ftlb.)±3 Nm (±2 ftlb.)
2 - Hydraulic belt tensioner; tensioner to lever - Tightening torque: 32 Nm (24 ftlb.)±3 Nm (±2 ftlb.) tensioning roller to tensioning lever - Tightening torque: 32 Nm (24 ftlb.)±3 Nm (±2 ftlb.)
3 - Screw, M8 x 96; complete lever to timing-case cover and cylinder head - Tightening torque: 32 Nm (24 ftlb.)±3 Nm (±2 ftlb.) belt tensioner and timing-case cover to bracket - Tightening torque: 32 Nm (24 ftlb.)±3 Nm (±2 ftlb.)
4 - Deflection roller - Tightening torque: 32 Nm (24 ftlb.)±3 Nm (±2 ftlb.)
5 - Dual poly-V-belt
4. Fit oil dipstick with guide tube and new sealing ring.
5. Fit drive belt.
6. Fit Y-pipe or intake pipes upstream of the throttle valve.