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Discussion Starter · #21 · (Edited)
I just torqued the cap to 18.4 lb-ft (25 Nm) and marked the cap's position relative to the housing. Even backed it off and torqued again several times to make sure the cap landed in the same place. I then took off the cap, put the washer in the erroneous position, and torqued the cap back down again. The cap was in the same rotational position each time. I then removed the washer forever.

This likely implies that the critical dimension for cap closure at spec'd torque is either the filter height or the cap threaded section/large o-ring, and that the bottom inner edge of the filter bottoms out on the housing (near item "13" on drawing) before or independently of the stem/washer. In other words, as unbelievable as this unforced error was, it may not have caused oil to bypass the filter or affected proper OF/OFH function. Maybe I'm wrong but would be curious to know others' thoughts on this assessment.
 

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I just torqued the cap to 18.4 lb-ft (25 Nm) and marked the cap's position relative to the housing. Even backed it off and torqued again several times to make sure the cap landed in the same place. I then took off the cap, put the washer in the erroneous position, and torqued the cap back down again. The cap was in the same rotational position each time. I then removed the washer forever.

This likely implies that the critical dimension for cap closure at spec'd toqure is either the filter height or the cap threaded section/large o-ring, and that the bottom inner edge of the filter bottoms out on the housing (near item "13" on drawing) before or independently of the stem/washer. In other words, as unbelievable as this unforced error was, it may not have caused oil to bypass the filter or affected proper OF/OFH function. Maybe I'm wrong but would be curious to know others' thoughts on this assessment.
Good to hear, and if those were your findings then it seems pretty clear there would have been no issue
 

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As long as you had oil pressure I think you are ok. I have seen many come in with cracked o rings, sounds like the cap sealed with the crush washer mod Lol . As long as your oil pressure light stayed off you should be fine.


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Discussion Starter · #25 ·
As long as you had oil pressure I think you are ok. I have seen many come in with cracked o rings, sounds like the cap sealed with the crush washer mod Lol . As long as your oil pressure light stayed off you should be fine.


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ROFL, a mod to avoid at all costs.
 

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Although final engineered parts differ from patent drawings, this shows the mating cylindrical surfaces could be slightly longer than needed.
The patent drawing shows a spring 17 pushing the center rod 3 down on surface 10, but I don't think E46 cap has this spring (the rod 3 is easily rotated against the cap 2). Cap 2 has a limiter 5 to give rod 3 some freedom axially for manufacturing tolerance to avoid crushing the rod disc 9 (or shoulder 9) when the cap 2 torqued down. But with the washer improperly added, the limiter 5 might have been crushed when the cap was torqued.

1) It seems the rod 2 small O-rings is ONLY for sealing of the drain hole 11 during operation, and allows the oil to drain when the rod 3 is pulled off the OFH. Then, what is the function of the hole on the rod between the 2 O-rings (shows on post #1)? Also, the 2 O-rings is to close or open the drain hole in the center located cylinder of the OFH, which has the filtered oil. Why the need to drain the filtered oil when changing filter? How is the dirty oil (outside the center located cylinder of the OFH) drained down when the cap is removed (there is a check valve down lower on the OFH near the OFHG)?
2) during operation, where is the filtered oil output port or hole? I don't see in drawings or pics within the filter section.
 

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Assuming the car run alright with no red oil light and there were no leaks from the oil filter housing cap, probably nothing dramatic happened.
I'd do an used oil analysis if that is still an option...
 

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Discussion Starter · #28 ·
Assuming the car run alright with no red oil light and there were no leaks from the oil filter housing cap, probably nothing dramatic happened.
I'd do an used oil analysis if that is still an option...
Great idea. I'll order a test kit from Blackstone.
 

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This likely implies that the critical dimension for cap closure at spec'd torque is either the filter height or the cap threaded section/large o-ring, and that the bottom inner edge of the filter bottoms out on the housing (near item "13" on drawing) before or independently of the stem/washer. In other words, as unbelievable as this unforced error was, it may not have caused oil to bypass the filter or affected proper OF/OFH function. Maybe I'm wrong but would be curious to know others' thoughts on this assessment.
The cap stopped due to its lip bottomed out on the aluminum housing top edge, not because the filter length or the center rod bottomed out. At 25Nm, even if the center rod crush washer was already bottomed, the torque would crush the rod limiter and you wouldn't know this.

1) was there a hole below the lower 2nd O-ring? If not why do they need the lower O-ring as the oil was sealed off by the upper small O-ring. I guess this depends on the function of the small hole on the center rod that I asked before.
 

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Discussion Starter · #30 · (Edited)
The cap stopped due to its lip bottomed out on the aluminum housing top edge, not because the filter length or the center rod bottomed out. At 25Nm, even if the center rod crush washer was already bottomed, the torque would crush the rod limiter and you wouldn't know this.

1) was there a hole below the lower 2nd O-ring? If not why do they need the lower O-ring as the oil was sealed off by the upper small O-ring. I guess this depends on the function of the small hole on the center rod that I asked before.
The cage/stem separate from the cap as shown here (not my video) e46 oil cap inside

With the cap removed, we can see that the actual design has no spring, and the limiter is a cylindrical boss (much more stable against buckling) rather than a rod as shown in the patent. I did pull the stem/basket off as I'd rather not create more problems by disassembling (possibly) old plastic, but when I wiped the old oil out of the cap assembly, I definitely didn't notice the sound of broken plastic rattling around, and the stem/cage in its seated position felt solid and completely concentric with the cap. Not the way to be 100% certain; might take a look at it in the AM again to check though.

Yes, I have the hole between the o-rings. I'm not 100% sure of its purpose. I stopped reading through the patent after a certain point, but I think the dual o-ring setup allows for both oil in the filtered AND unfiltered sections to drain back to the sump. Clearly, the upper ring is for clean oil to drain. I think the middle chamber (between the two o-rings) is connected to the unfiltered portion of the OFH. When the cap is pulled the lower seal is also undone, and my guess is that all the unfiltered oil in the OFH then drains from the middle chamber into the lowest portion shown in the cutaway (back to the sump). The middle and lowest chambers of the cutaway view might be reversed from that, but with enough pressure / height of unfiltered oil, it could still mostly drain.

Why the need to drain the filtered oil when changing filter?
I think you'd want old filtered oil to drain from the OFH to the pan to get rid of as much old oil as possible during the change.

How is the dirty oil (outside the center located cylinder of the OFH) drained down when the cap is removed (there is a check valve down lower on the OFH near the OFHG)?
Good question. When initially took out the old filter, there was still a little left at the bottom of the outer unfiltered portion that I vacuum pumped out. Maybe the rest that drained bypassed the check valve?

2) during operation, where is the filtered oil output port or hole? I don't see in drawings or pics within the filter section.
The two cross sections shown are insufficient to fully explain the design, but I'm pretty sure the middle portion goes to the OFH filtered outlet, and the section view on the patent just doesn't show it due to being a non-rotationally symmetric part. Not 100% on this but there'd be nowhere else for filtered oil to go, based on other posts I've read. Image credit to fanatichuman's post showing the below view of the OFH: Is this oil level low and a sign that my drain back...

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OP, From the video and my memory, I think the pointed tip of the rod also has a hole, please verify.
As seen in above pic, the center cylinder wall is quite tall, so I don't think the unfiltered oil can flow into the center well and drain off when the cap is removed. And if the lower check valve working, then the dirty oil cannot drain back via the pump. So how did the dirty oil drained when the cap is pulled off? The purpose of the check valve is to keep the dirty oil in the filter with engine turned off.

The above pic also shows the filtered oil flows down in the well, then maybe pass through a hole and into the horizontal pipe (3:30 o'clock position in pic) and down to the block.
 

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Discussion Starter · #32 · (Edited)
OP, From the video and my memory, I think the pointed tip of the rod also has a hole, please verify.
As seen in above pic, the center cylinder wall is quite tall, so I don't think the unfiltered oil can flow into the center well and drain off when the cap is removed. And if the lower check valve working, then the dirty oil cannot drain back via the pump. So how did the dirty oil drained when the cap is pulled off? The purpose of the check valve is to keep the dirty oil in the filter with engine turned off.

The above pic also shows the filtered oil flows down in the well, then maybe pass through a hole and into the horizontal pipe (3:30 o'clock position in pic) and down to the block.
I don't recall if the tip had a hole in it. I think it was only between o-rings. I could be wrong but image search will reveal, e.g. this thread: Small o rings in the oil filter cap shaft .

Note: please do not rely on the below explanation as fact if you have some critical issue. I'm just taking an educated guess here based on a few hours of research, and this gives me enough confidence that my engine isn't messed up.

See color coded diagram. Each color indicates a continuous chamber. I have a feeling the outlet for filtered oil to the engine isn't revealed by the cross section (i.e. it's hidden). I don't have a spare OFH to investigate flow but one could confirm this easily with a spare, in terms of which chambers connect to what outlets/inlets.

I think the check valve is only connected to the inlet of unfiltered oil chamber. Thus unfiltered oil would completely bypass the check valve via the drain when the cap is off (red arrows).

As mentioned earlier I observed a little oil leftover at the bottom of the unfiltered chamber. This would corroborate the flow diagram, because any oil in the unfiltered chamber below the height of the drain entry (where the arrows are) wouldn't escape, even with the cap off. In other words, any oil in the unfiltered chamber above the level of the drain entry will escape when the cap is removed.

Map Slope Yellow Rectangle Line
 

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I think the middle chamber (between the two o-rings) is connected to the unfiltered portion of the OFH.
This is possible only if the bottom of the diry oil chamber is connected to the center chamber (between the O-rings) via the horizontal pipe at 3:30 o'clock position in post 30 pic.

I think the filtered oil flows out via a short horizontal pipe located at 9:30 o'clock in post #30 pic.

I think this is how it works:
The center rod has a long center hole from the top down to and exit at the section D between the 2 O-rings. The outside dirty oil in the OFH also has a hole connected to the section D via the horizontal pipe (3:30 o'clock).
The upper O-ring seals off the filtered oil from entering section D, and the lower O-ring seals off the dirty from draining down a drain hole DH below the lower O-ring. So when the cap was pulled off, the remain filtered and dirty oil drain down via the bottom hole DH.
Why the rod needs the hole between the 2 O-rings?

The explanation in pic below doesn't make sense: Unfiltered oil cannot drain from 3 down to 4 via the rod center hole, as 3 will be above the oil level when the cap is pulled up. So what is the rod center hole for?
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Discussion Starter · #34 · (Edited)
The upper O-ring seals off the filtered oil from entering section D, and the lower O-ring seals off the dirty from draining down a drain hole DH below the lower O-ring. So when the cap was pulled off, the remain filtered and dirty oil drain down via the bottom hole DH.
I mentioned that is possible in post #30. But note that the patent refers to drain 11 (middle chamber).

Why the rod needs the hole between the 2 O-rings?
If connected to the top, like you say, it might be a release path for excess oil to drain so the entire filter housing doesn't get over-pressurized oil. i.e. the oil in the filter housing would have to be 99% full and anything above that would automatically get drained. Other than that I have no idea.

The explanation in pic below doesn't make sense: Unfiltered oil cannot drain from 3 down to 4 via the rod center hole, as 3 will be above the oil level when the cap is pulled up. So what is the rod center hole for?
I think the poster of that picture was illustrating where oil exits at corresponding to the position on the OFH for #4, not in terms of exiting via the cap itself. For the rod center hole, see last paragraph.
 

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If connected to the top, like you say, it might be a release path for excess oil to drain so the entire filter housing doesn't get over-pressurized oil. i.e. the oil in the filter housing would have to be 99% full and anything above that would automatically get drained. Other than that I have no idea.
We agreed that the section between the 2 O-rings is unfiltered oil, but I don't think the rod hole has anything with releasing over-pressurized oil or oil level in the housing. I think it is for unfiltered oil to flow into the rod bottom hole then out at the rod top to the outside of the filter element. IOW the unfiltered oil is pumped up into section D then into the rod and out at the rod top to be filtered. This is to avoid the unfiltered oil to flow outward into the outer section of the paper filter via the 3:30 pipe as the flow here will disturb the dirty settlement at the bottom of the paper element.
 

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Amazing, some idiots just have to find a place to use the crushed washer. He thought the supplied O-rings and the washer must somehow be fitted inside the filter. That crusher washer is for the pan drain bolt.
...so you think they simply saw "hey what a beautiful washer! don't know where it goes, why not to put it here?"
XD

what worries me is that extra tickness added to the torque to stretch the cap would have somehow "forced" the plastic axle or give tension to the filter walls on point n.9 on the pic
Map Slope Triangle Font Schematic
 

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Discussion Starter · #37 · (Edited)
We agreed that the section between the 2 O-rings is unfiltered oil, but I don't think the rod hole has anything with releasing over-pressurized oil or oil level in the housing. I think it is for unfiltered oil to flow into the rod bottom hole then out at the rod top to the outside of the filter element. IOW the unfiltered oil is pumped up into section D then into the rod and out at the rod top to be filtered. This is to avoid the unfiltered oil to flow outward into the outer section of the paper filter via the 3:30 pipe as the flow here will disturb the dirty settlement at the bottom of the paper element.
Honestly I don't think the area between the o-rings is the unfiltered oil supply, I merely proposed the possibility because the drawings weren't entirely clear on first glance. See my earlier posts; I am confident, per the patent, that it is the drain. You also quoted the patent as the middle being the drain chamber 11. It allows both unfiltered and filtered oil to flow to the pan when the cap is removed. I am 99.9% sure the unfiltered oil supply that goes to the filter does not flow through that tiny rod how you describe; it flows up and around the sides of the filter. From a mass flow rate perspective, it makes no sense to flow through the center of the stem, if indeed it's even hollow. The cross sectional area is way too small and restrictive.

See these posts on general oil flow direction:
 

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I merely proposed the possibility because the drawings weren't entirely clear on first glance. See my earlier posts; I am confident, per the patent, that it is the drain. You also quoted the patent as the middle being the drain chamber 11. It allows both unfiltered and filtered oil to flow to the pan when the cap is removed.
We didn’t know much at the beginning so I also assumed section D is connected to drain 11 as shown on the patent.
However. If section D is the drain then why the rod needs the lower O-ring, and what is the space below the lower o-ring?
I am now saying the drain hole is below the lower o-ring.
 

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back to OP, I m going to monitor at all oil change if I see the washer there or not. can t image it would make any difference
 

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Discussion Starter · #40 ·
We didn’t know much at the beginning so I also assumed section D is connected to drain 11 as shown on the patent.
However. If section D is the drain then why the rod needs the lower O-ring, and what is the space below the lower o-ring?
I am now saying the drain hole is below the lower o-ring.
See the color-coded diagram in post 32 and its red arrows indicating flow direction when the cap is removed. I'm pretty sure the lowest chamber is connected to the main unfiltered oil chamber.
 
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