DIY: Oil pump replacement

[nicke_1]

Oil pump replacement



While doing my rod bearings I thought the it would be a good time to replace the oil pump as the oil pan was down. Got a good deal on a new pump and changed it before finishing the rod bearing job.

The DIY does not include the steps on lowering/removing the subframe, taking down the oilpan etc. I would suggest to do what is covered in SYT_Shadow's excellent DIY for changing the rod bearings: https://www.m3post.com/forums/showthread.php?t=1333638 This guide starts after the two oil pipes has been removed.

Time taken: 1hrs

Tools needed:
Torx T30
Torx T45
16mm wrench
Torque wrench
Picking tool
Green Loctite
Blue Loctite

Torque specs:
Oil pipes: 10Nm
Oil pump sprocket nut: 25Nm
Oil pump to engine: 22Nm

Part numbers:
1 x 11417838311 Oil pump
1 x 11427838016 Oil pump gasket
1 x 11417839832 Oil pump pipe oring (25x2mm)
1 x 11417839833 Oil scavenge pump o-ring (19x2mm)
1 x 11417837553 Oil pump sprocket retaining nut (M10)
2 x 07129904819 Torx bolt for oil pipes (M6X16-8.8)

Part numbers (optional):
1 x 11417838521 Oil pump sprocket wheel
1 x 11417838522 Oil chain guide rail
1 x 11417838523 Oil chain tensioner
1 x 11417836796 Chain
5 x 07129905692 ISA screws with washer (M6X20-8.8) for oil pipe bracket + oil pipes
1 x 11417838534 Suction pipe gasket

Procedure:

1. Remove the oil pump nut (16mm). On the picture you can see that I have marked the front of the sprocket with an "V" for "Vorne" - "Front" in german, so I would know which way the sprocket was mounted before taking it down. This was unnecessary since there is text stamped on the front side and you can identify it through that!


2. Remove the chain guide rail (two T30 bolts).


3. Wiggle the sprocket off the oil pump.


4. Let the chain hang on the sprocket on the scavenge pump. Inspect the chain, sprocket, guide rail and tensioner. Replace if necessary. Mine had 120854 km/75095 miles on them and I chose not to replace them.


4. Loosen the three bolts securing the oil pump (three T45 bolts). Hold the oil pump with one hand and unscrew the last of the three bolts with the other hand. The pump sits on two dowels and they might resist on letting the pump get off the crank case. (On the picture you can see that the chain is still attached to the oil pump, please disregard that - mixing up the pictures!)


6. Remove the oil pump gasket from the crank case with a picking tool. Clean up the crank case with Brakecleen and a clean lint free cloth. I used micro fiber towels.


7. Clean up the bolts that is going to be reused, as well as the threads in the engine block with Brakecleen and compressed air.


8. Put the sprocket wheel on the new oil pump and use a new nut. The new nut from BMW has already got some green thread locker on it. I did also put a dab of high strength (green) thread locker on the thread of the oil pump shaft. Torque the nut to 25Nm (16mm). I secured the sprocket wheel in a vice grip with soft pads and torqued the nut from underneath.


9. Insert a new oil pump gasket.


10. I filled the new pump with 10W-60. A bit messy when reassembling things, but felt good that the new pump has some oil in it upon the first startup after rod bearing change as well as oil pump change.


11. With the oil chain still hanging on the sprocket of the scavenge pump locate the oil pump sprocket in it and "fold" up the pump to the crank case.


12. Start threading in the three bolts by hand making sure that the pump goes in straight and is seated on the dowels.


Torque the three bolts to 22Nm (T45).


13. Install the guide rail with the two M6 bolts (T30) and torque them to 10Nm.


15. Install the oil pipe bracket. My new M6 bolts already had their threads coated with pink(?!) thread locker. If yours does not I'd use a tad of medium strength (blue) thread locker. Tighten the four M6 oil pipe bracket bolts to 10Nm (T30).


15. Replace the o-rings on the oil pipes. Lubricate the o-rings with engine oil and install the oil pipes with new M6 screws (T30) for pipe to scavenge pump as well as pipe to oil pump. Secure the pipes to the oil pipe bracket with three hex bolts (10mm) and one torx bolt (T30) to the crank case after applying some medium strength (blue) thread locker to the bolts. Torque to 10Nm.

16. Reassemble the oilpan, subframe etc according to SYT_Shadow's DIY.

[Helmsman]

Wow, yet another beautiful post and pictures Nicke!

[Redd]

Sorry for reviving this old thread.

Is it recommended to preventively replace the oil pump? If yes, at what mileage.

I will be doing my 2nd rod bearing replacement at 170k kms (another 10k to go) and wondering if I should do the oil pump at the same time. There's currently no issues at all with the car.

[charliev68]

DIY is missing one important step of setting the gear lash free play!
Oil pumps are usually not a maintenance issue.

[nicke_1]

Backlash for the gearwheel is set for the oil scavenge pump. In other words, you do not need to set the gear lash free play when replacing or reinstalling the oil pump.

Originally Posted by charliev68

DIY is missing one important step of setting the gear lash free play!
Oil pumps are usually not a maintenance issue.