Oil Pressure Sender: Service and Repair
WM 170419 Removing and installing oil pressure sensor on 4.8-litre DFI engines
Technical values
Preliminary work
Information
If vehicles have fault entries relating to oil pressure, oil pump activation, oil pressure monitoring, etc. in the DME control unit (and a warning light comes "on" on the instrument cluster), proceed as follows:
- Check the oil level.
- Delete related faults.
- Do not replace components, such as the oil pump, oil pressure sensor or oil pressure control valve if you suspect that they are faulty.
If the vehicle has not been driven for a long time (months), the control mechanism in the oil pump can become stiff ("stick").
Very short trips and a lot of loading/manoeuvring can cause the oil to become very diluted => Oil pressure very low. For example, 20 cold starts in quick succession can reduce the viscosity of the engine oil by 30%.
- Change the engine oil. Test-drive the vehicle.
- If error messages/warnings are displayed again, proceed in accordance with the instructions under Guided Fault Finding in the PIWIS Tester.
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. -> 243519 Removing and installing air box for throttle housing on DFI engines (intake pipes upstream of throttle valve) - section on "Removing" Service and Repair
2. Remove drive belt in the area of the lower deflection roller. For details, see -> 137819 Removing and installing drive belt on 4.8-litre DFI engines - section on "Removing" 137819 Removing and installing drive belt on 4.8 l DFI engine
3. Remove oil dipstick with tube. -1-
Oil guide housing with accessories
4. Remove deflection roller between the vibration balancer and the generator. To do this, use a small screwdriver to prise off the lid and loosen the screw. Remove deflection roller with screw. -1-
Belt drive
Removing oil pressure sensor
1. Pull off cable plug for oil pressure sensor.
2. Place a cloth around the components. Collect dripping oil.
3. Remove oil pressure sensor (oil pressure sender) with adapter -3 and 1-. To do this, remove the two screws -4- and pull the components straight off. Replace sealing rings.
Oil pressure sensor and oil pressure measuring point
Installing oil pressure sensor
1. Clean all traces of oil from installation location of oil pressure sensor.
Information
Do not turn the oil pressure sensor in the adapter. Risk of breakage.
Do not break off sensor tips. Insert carefully.
2. Move oil pressure sensor (oil pressure sender) with adapter and new sealing rings into installation position -3 and 1-. Position and fit the two screws -4-.
Oil pressure sensor and oil pressure measuring point
3. Connect cable plug for oil pressure sensor.
Subsequent work
1. Fit deflection roller between the vibration balancer and generator -1-. Position deflection roller with screw and tighten the screw. Press on lid.
Belt drive
2. Fit oil dipstick with tube -1-. Use new sealing rings.
Oil guide housing with accessories
3. Fit drive belt. For details, see -> 137819 Removing and installing drive belt on 4.8-litre DFI engines - section on "Installing" 137819 Removing and installing drive belt on 4.8 l DFI engine
4. Fit Y-pipe or intake pipes. -> 243519 Removing and installing air box for throttle housing on DFI engines (intake pipes upstream of throttle valve) - section on "Installing" Service and Repair