Oil Pump: Service and Repair
WM 172019 Removing and installing oil pump
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/manoeuvreing 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 oil pan and oil guide housing.
-> 175019 Removing and installing oil guide housing 175019 Removing and installing oil guide housing
Information
Component overview
Oil lines, intake manifold on turbo engine
Oil lines, intake manifold on naturally aspirated engine
Oil pump on turbo engine with oil extraction stage
Oil pump on naturally aspirated engine
Information
- The tightening specifications for the basic engine are stored centrally. -> 1001IN Tightening torques, tightening sequences, assembly overviews [1][2]Specifications. Tightening torques and assembly instructions for other assemblies (e.g. chassis, electrics, transmission or body) or for peripheral engine equipment can be found in the corresponding documents.
Information
- The oil pump must not be disassembled and reassembled!
- When carrying out work on the oil circuit, it must be ensured that no dirt gets into the engine!
Information
- The oil pump can be replaced while installed.
Removing oil pump
1. Disconnect lines at the oil pump.
1.1. Remove the two screws on the intake manifold and take the intake manifold off the oil pump. -3-
Oil return
2. Remove the sprocket cover for the oil pump
2.1. Loosen the top screw -1- using an open-ended wrench until the sprocket cover is released. Remove the two remaining screws. -2 and 3-
Sprocket cover mounting
2.2. Pull the sprocket cover down and off. The top hole is open. => Top threaded joint on sprocket cover
Top threaded joint on sprocket cover
3. Remove the oil pump drive sprocket.
3.1. Position vibration balancer with screw tightened hand-tight on the crankshaft stub. Attach change-over ratchet. => Sprocket screw
Sprocket screw
3.2. Loosen screw on sprocket. Use an extension if necessary because the screw is very tight -1-. Counter at the vibration balancer using the change-over ratchet. Screw is tightened beyond the elastic limit. => Countering oil pump pinion Use a screwdriver to counter at the oil pump through a bore in the drive pinion if necessary. The loosened screw must not be re-used.
Countering oil pump pinion
4. Press off small tensioning rail on the chain -arrow- using a screwdriver => Oil pump drive chain and remove the sprocket from the pump. Loosen the tensioning rail slowly. The chain remains fitted.
Oil pump drive chain
5. Remove oil pump
5.1. Unscrew screws on the oil pump -2-. Hold the oil pump securely.
Oil pump screws
5.2. Carefully loosen the locking hook on the joining socket using a screwdriver => Disconnecting pipe and carefully remove the oil pump.
Disconnecting pipe
Installing oil pump
Information
- The tightening specifications for the basic engine are stored centrally. -> 1001IN Tightening torques, tightening sequences, assembly overviews [1][2]Specifications. Tightening torques and assembly instructions for other assemblies (e.g. chassis, electrics, transmission or body) or for peripheral engine equipment can be found in the corresponding documents.
1. Fit the oil pump
1.1. Lubricate sealing rings on joining socket -5- with lubricant 000 043 204 68 (status 05/07)
Oil guide (oil plate)
1.2. Carefully move oil pump into installation position.
1.3. Connect oil pump and joining socket together. The locking mechanism must clip in (on socket fitted in the oil pump).
1.4. Fit three screws on the oil pump -2-.
Oil pump screws
1.5. Screw intake manifold to the oil pump. -3-
1.6. Tighten three screws on the oil pump. -2-
2. Press off small tensioning rail on chain -arrow- using a screwdriver => Oil pump drive chain , insert sprocket and fit it on the pump. Insert new screw and screw it in hand-tight.
Oil pump drive chain
3. Fit the oil pump drive sprocket.
3.1. Fit vibration balancer with screw tightened hand-tight on the crankshaft stub => Sprocket screw. Attach change-over ratchet.
Sprocket screw
3.2. Fit screw on sprocket. Use an extension if necessary due to the very high tightening torque -1-. Counter at the vibration balancer using the change-over ratchet. Tighten the screw in two stages.
3.3. => Countering oil pump pinion Use a screwdriver to counter at the oil pump through a bore in the drive pinion if necessary.
Countering oil pump pinion
4. Fit oil pump sprocket cover.
4.1. Slide in sprocket cover in an upward direction. The top hole is open. Screw is still fitted, but loosened. => Top threaded joint on sprocket cover
Top threaded joint on sprocket cover
4.2. Tighten the top screw -1- using an open-ended wrench (tighten slightly by hand). Fit the two remaining screws. -2 and 3-
Sprocket cover mounting
5. Check that the tensioning rail and drive chain are positioned correctly.
Subsequent work
1. Install oil pan and oil guide housing. -> 175019 Removing and installing oil guide housing 175019 Removing and installing oil guide housing