Oil Pump Question

[ingramlee]

I am replacing my original oil pump with the E21 pump and reusing the pick-up. The original M10 pump two O-rings  #7 at the bottom and top of pickup tube, but the realoem diagram for the E21 pump only shows the O-ring at the top of the tube #20 where the tube mounts to side of block. Is the lower O-ring where the tube enters the pump needed for the E21 pump? See both pumps below.

 

 

 

Thanks

 

 

 

 

[jimk]

Yes, use both or the pressure control valve will not be getting the galley pressure. (Besides, there is a qty of 2 in the parts list.)

For the record, the tube supplies pressure to the pump pressure control valve and carries the relieving flow, not a pickup tube.

Edited February 10, 2018 by jimk

[TobyB]

While you're there, make sure the dimple in the relief tube, visible in the above pic, seats down inside the aluminum

of the oil pump itself.  If it doesn't do so very positively, the o- ring (that you very much do need, btw)

will get extruded out of the gap, and let oil leak down out of the main galley when the car sits.

 

That stinks.

 

BMW made them at least 2 different ways, and some fit better than others.

 

t

 

[worzella]

Hi - just went through this recently and a few more tips to add to your anxiety:

 

o Make sure you have washer #7 BEHIND the sprocket like lower picture shows.

o Make sure you have the right "thin" nut #18 on lower picture 

o Make sure you Loctite that nut when you tighten it also

o Since this is the "heart" of your car, consider replacing the main body shim #4 lower diagram. Mine was pretty worn when I split my old body and pickup.

o Save time and order a handful of the shims #15 since with new chain and sprocket, you might need some jiggering to get proper fitment. I believe there are two thicknesses available.

 

Lots of other posts with these details, but those were the notes I took and made sure I followed.

 

Randy 

[ingramlee]

Randy,

 

All good comments that I plan to follow, however, I do have two quick questions regarding your comments.

 

Why would I need to replace #4 body shim on a new pump? 

Do you know the size and thickness of the #7 washer behind the pump

 

Thanks

[worzella]

The pump pickup and body are aluminum and the shim is steel. As the new pump becomes old pump some minute slop may come about and the impeller (#5 & 6) may have some axial play. Instead of them grinding against the aluminum pickup they grind against steel. So it is sort of a sacrificial plate... it might take 30 years to worry about it, but for a few bucks, might be worth it when you have things apart.

 

Let me check if I can find that part number and size info. Be right back

 

Randy 

[worzella]

07

Shim

12X18X1,7

1

07119932634

 

I do not know my "nut" specifications, but 12x18x1.7 is the spec. 

 

BLUNT can certainly get you the #4 shim and nut, or I just looked up on the Maximillian Mobile Tradition site and the nut is 29 cents and the #4 is listed at $10. Of course, they charge probably $20 to ship, but such is life. 

 

I think people have said it is hard to find that "thin" nut in the usual Ace/HD/Lowes but maybe try Fastenal... 

 

Randy 

[NickVyse]

new shim comes with a new pump. so should a nut and washer

[ingramlee]

Hi Randy,

 

Thanks again. Clearly #4 is a shim. #7 is basically a washer, or shim I suppose. Correct?

[jimk]

#4 is a wear plate that takes the pressure thrust of the impeller against the suction housing.  There is 60-150 psi oil pressure on the discharge side of the impeller and a slight negative on the suction side.

Early pumps did not have this plate and the end housing was always gouged and worn.  It's a throw away part and meant to be replaced on used pumps.  My Sept 71 build car did not have the plate.  It doesn't shim anything for the purpose of shimming.  It fits and can be added to a pump that is without.

[kbmb02]

Ingramlee ... back to your original inquiry: Look at and/or post a photo of your original pump pickup; the reason for the ‘intermediate plate’ (as BMW calls it, and as jimk explains it) will become more clear. -KB

[ingramlee]

KB-

It is very clear now- thanks to Worzella. In my haste and carelessness when I removed the E21 pickup from the new pump and set it aside the intermediate plate or shim stayed attached to the pickup and I didn't see it so i unfortunately assumed I didn't have one, I do, what I don't have is the #7 washer or shim as BMW calls it that goes between the sprocket and the pump housing. Maybe,(but I doubt it) this washer will be included with the new sprocket that I'm waiting to arrive.

 

My original inquiry referred to the 2 O-rings for the hard tube- top and bottom. I think the consensus is I need them both even though only one is shown on the bottom photo. My other question was regarding the washer behind the sprocket. I think I now have the size that I need for that.

 

Thanks-

[worzella]

BMW parts diagram calls them both "shims" for some reason. The washer one is more of a spacer to keep the sprocket aligned on the shaft as designed.

 

If you ordered a new pump it sounds like you should get the shim/washer and the nut... but not sure how you acquired the pump.

 

Have fun!!

[ingramlee]

When I received the new pump it came with the larger shim and the mounting nut but not the smaller shim for behind the sprocket. 

 

Thanks

[xr4tic]

If you're replacing the oil pump chain as well, buy a factory BMW one.  A lot of the aftermarket chains are wrong (thicker) as pointed out in this thread:

When I put a new chain on mine, I had to remove the shim between the oil pump and block because it was so much tighter.