quick question, oil pump

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four2zerohero
Posts: 311
Joined: Jul 01, 2010 8:09 PM
Location: Tucson Az

quick question, oil pump

Post by four2zerohero »

Is shimming an oil pump better than leaving it as is if the chain has wear? I am replacing my oil pan gasket and as you know the potential for mission creep is high. I'm on a tight budget, and it seems like replacing the chain requires replacing the sprocket which is a special order item.
is shimming the pump better than nothing?

Thank you
BMWCCA2
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Re: quick question, oil pump

Post by BMWCCA2 »

I think you should shim the pump regardless of whether or not you replace the chain.

A couple of years ago I replaced the pump and shimmed it but did not replace the chain or sprocket. Seems to be working fine. Oil-pressure lamp goes out almost before the engine catches!
SlickDizzy
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Re: quick question, oil pump

Post by SlickDizzy »

If you are in that far, I would highly recommend you spend a few extra minutes to split the oil pump halves and replace the “wear plate” inside, which is a sacrificial piece meant to prevent housing wear. Between that and the shimming you should buy yourself a fair amount of time until you can do the whole job.

#12 in the attached diagram, they cost a whole five dollars from BMW.

https://www.realoem.com/bmw/enUS/showpa ... Id=11_2122

Replacing the pressure relief spring (#21) is also not a bad idea and is very quick and easy to do, though probably not as necessary.
four2zerohero
Posts: 311
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Location: Tucson Az

Re: quick question, oil pump

Post by four2zerohero »

Thank you gentlemen,
BMWCCA2 wrote: Nov 12, 2020 8:47 AM I think you should shim the pump regardless of whether or not you replace the chain.

A couple of years ago I replaced the pump and shimmed it but did not replace the chain or sprocket. Seems to be working fine. Oil-pressure lamp goes out almost before the engine catches!
so would a couple of the 1.0mm shims stacked upon each other work? i cant find anywhere that sells the 3.0mm one,
four2zerohero
Posts: 311
Joined: Jul 01, 2010 8:09 PM
Location: Tucson Az

Re: quick question, oil pump

Post by four2zerohero »

SlickDizzy wrote: Nov 12, 2020 8:54 AM If you are in that far, I would highly recommend you spend a few extra minutes to split the oil pump halves and replace the “wear plate” inside, which is a sacrificial piece meant to prevent housing wear. Between that and the shimming you should buy yourself a fair amount of time until you can do the whole job.

#12 in the attached diagram, they cost a whole five dollars from BMW.

https://www.realoem.com/bmw/enUS/showpa ... Id=11_2122

Replacing the pressure relief spring (#21) is also not a bad idea and is very quick and easy to do, though probably not as necessary.
Thank you, this is the mission creep i could afford. May be a silly question, but should I still lap the housing halves to ensure they're true?
SlickDizzy
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Re: quick question, oil pump

Post by SlickDizzy »

four2zerohero wrote: Nov 12, 2020 10:19 AM
Thank you, this is the mission creep i could afford. May be a silly question, but should I still lap the housing halves to ensure they're true?
I wouldn’t bother, the softer metal wear plate acts as a gasket of sorts.
four2zerohero
Posts: 311
Joined: Jul 01, 2010 8:09 PM
Location: Tucson Az

Re: quick question, oil pump

Post by four2zerohero »

SlickDizzy wrote: Nov 12, 2020 10:44 AM
four2zerohero wrote: Nov 12, 2020 10:19 AM
Thank you, this is the mission creep i could afford. May be a silly question, but should I still lap the housing halves to ensure they're true?
I wouldn’t bother, the softer metal wear plate acts as a gasket of sorts.
good to know

thanks again
four2zerohero
Posts: 311
Joined: Jul 01, 2010 8:09 PM
Location: Tucson Az

Re: quick question, oil pump

Post by four2zerohero »

okay, another question.
I've got my pump removed and on the bench and disassembled. It turns out it already had one set of shims installed. My question is can i stack up various 0.01mm shims to take up the slack? will the oil leak through them if i do? I ask about the 0.01mm shim because i cannot seem to find the 0.03mm one anywhere.


thank you.
WVe28
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Re: quick question, oil pump

Post by WVe28 »

Yes you can stack them. I ended up with three each on mine.
ahab
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Location: Chalfont, PA

Re: quick question, oil pump

Post by ahab »

WVe28 wrote: Nov 17, 2020 10:59 AM Yes you can stack them. I ended up with three each on mine.
Was that before or after the "quart erry hunnert" problem?? :rofl:

All kidding aside, did you figure out what what wrong?
four2zerohero
Posts: 311
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Location: Tucson Az

Re: quick question, oil pump

Post by four2zerohero »

i wanted to thank all who had given suggestions on this thread. I finally received some special order parts: 2 front and 2 rear shims, intermediate plate and compression spring. After studying the realoem diagram and comparing to my own pump, i can see that i am missing parts: 20-piston and 22-screw plug. Mine only had the spring, spring pocket and the lockring, it wasnt under pressure even with the new spring (which BTW didnt seem too different from the one that was there.

Am I good just running the spring alone?

thank you all again

-Ricardo
SlickDizzy
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Re: quick question, oil pump

Post by SlickDizzy »

#22 wasn’t used on most pumps (it is greyed out on the RealOEM diagram for my car and was not present during rebuild) but the #20 piston is absolutely required for the pump to function as designed.

The purpose of the spring and piston is to provide pressure relief/regulation to prevent an over-pressurized scenario. If you really just have no piston at all, that’s...not good.

The spring has no function without the piston, it would just be a loose spring bouncing around in your oil pump. So you really do need both. Are you sure the piston isn’t just stuck in the pump body?

As far as the spring replacement, my original was about ~4mm shorter than the new replacement at ~200k miles, which means the spring was losing tension and my oil pump was potentially relieving pressure more than spec. Seemed like a good call to replace it, cheap insurance at least.
four2zerohero
Posts: 311
Joined: Jul 01, 2010 8:09 PM
Location: Tucson Az

Re: quick question, oil pump

Post by four2zerohero »

Thank you Slickdizzy
I don't see how the piston could be stuck to the pump body if the replacement spring just went in with no resistance. Either way I will order one, i'm in no rush as im buttoning up other things.

Again, thanks for your response.
four2zerohero
Posts: 311
Joined: Jul 01, 2010 8:09 PM
Location: Tucson Az

Re: quick question, oil pump

Post by four2zerohero »

SlickDizzy wrote: Dec 31, 2020 12:44 AM . Are you sure the piston isn’t just stuck in the pump body?
SlickDizzy,
i wanted to thank you once again for your guidance, the old piston was indeed stuck to the pump body.
the pumpwas already mounted to the engine and i was just going to replace that broken lockring but i looked up and saw the stuck piston, Luckily i already had the replacement one on hand since i thought it was a solid piece but its hollow on one end. It was hard to remove from the pump with the pump mounted on the motor but a number 4 extractor did the job.
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