This is not helpful. If you think I'm wrong then just simply state the fact with your measured data.Really?
This is not helpful. If you think I'm wrong then just simply state the fact with your measured data.Really?
Olive oil just don't flow out of olive; it needs to be compressed.
I 100% agree been working on BMWs for 25+ years and if the oil pressure light is off then it is making correct pressure and there’s no reason for oil starvation. build a hundred plus engines including NASCAR cup engines and you have a great idea how the oil flows and your situation I wouldn’t give a second thought. I would put the new filter in correctly and fill with oil and be done. That little bit of oil in the filter housing is totally normal every bmw I have changed oil on always has a little old oil in there.Well I just refuse to believe that there's going to be any relevant drop of oil pressure from before/after the filter.
I think you missed the point that the OP and I was discussing.I 100% agree been working on BMWs for 25+ years and if the oil pressure light is off then it is making correct pressure and there’s no reason for oil starvation. build a hundred plus engines including NASCAR cup engines and you have a great idea how the oil flows and your situation I wouldn’t give a second thought. I would put the new filter in correctly and fill with oil and be done. That little bit of oil in the filter housing is totally normal every bmw I have changed oil on always has a little old oil in there.
One of the worst oil filter snafu I have encountered was on a e32 740i about 20 years ago and it hadn’t been changed in over 40,000 miles. The guy would drain the oil and not change the filter. He couldn’t get it lose. When I got ahold of it I had to vacuum what was left of the filter out with the shop vac. Just put a new one in it and new oil and it had the correct pressure because I took the sensor out and installed a gauge to see what it actually was and it was in spec no lifter noises.
Like the "normal engineer" who designed the M54's CCV system? I never claimed it would be a good idea to design this way. I'm just throwing out a possibility that you could still achieve sufficient pressure and mass flow rate to the gallery, in response to your view that the stem hole goes all the way to the top and therefore the drain to sump must be the center/bottom portion of the OFH. We can debate the stem hole tangent, but isn't it irrelevant to your original question with the below picture? If you think the drain is bottom/center, why is there leftover oil at that location after unscrewing the cap??No normal engineer would design the system such that to waste the valuable pressurized oil going down the drain via the 4mm hole. so by logical reasoning, the assumption cannot hold even with measured data.
This is not helpful. If you think I'm wrong then just simply state the fact with your measured data.
The oil pressure switch or sensor is located in the filtered oil path, not the pump's output dirty oil which is much higher than 50 psi.
Did you measure unfiltered pressure, and if so at cross section are you measuring? Maybe I'm wrong but it comes across that you are presenting a hypothesis without data, and then telling someone else who has a different hypothesis that only they must supply the evidence?I would think at least 10 psi warm oil , and higher with cold oil.
It is hard to see the detail of the bottom hole in that pic -- quite deep in the small tube.We can debate the stem hole tangent, but isn't it irrelevant to your original question with the below picture? If you think the drain is bottom/center, why is there leftover oil at that location after unscrewing the cap??
If you haven't, try right-click -> open image in new tab for full size version. You can see the flash from camera reaches all the way to what appears to be a pool of oil and creates a reflection; it's more oil than just amber coating on the surface of metal (BTW oil in the pic is fresh / has less than 100 miles on it).It is hard to see the detail of the bottom hole in that pic -- quite deep in the small tube.
So there are 2 O-rings on the center rod, inserted in the tube, to create 3 separate chambers.
The top one is the filtered oil chamber.
Middle one: you proposed this connected to drain tube 11
Bottom one: TBD
What I'm saying is that your theory doesn't make sense of why it needs the bottom chamber. Why it doesn't have just one O-ring to create only 2 chambers?
I buy this, but it doesn't makes sense with the center rod hole connected to the drain tube 11. I need to blow into the rod holeYes, you'd definitely need two o-rings to drain both those chambers. The top o-ring prevents filtered oil from draining while the cap is on. Cap off and filtered oil drains per the orange arrow. The bottom o-ring separates unfiltered oil from the drain while the cap is on. Unfiltered oil drains per the red arrow when the seal is broken. If you wanted to design another OFH and put the drain on the bottom and unfiltered oil connected to the middle, I think you could do that / mechanically it'd work fine. However, on this particular OFH, the fact that there is leftover oil in the bottom center hole (per the above picture) suggests that the center is not the drain.
If you think the drain is bottom/center, why is there leftover oil at that location after unscrewing the cap?Like the "normal engineer" who designed the M54's CCV system? I never claimed it would be a good idea to design this way. I'm just throwing out a possibility that you could still achieve sufficient pressure and mass flow rate to the gallery, in response to your view that the stem hole goes all the way to the top and therefore the drain to sump must be the center/bottom portion of the OFH. We can debate the stem hole tangent, but isn't it irrelevant to your original question with the below picture? If you think the drain is bottom/center, why is there leftover oil at that location after unscrewing the cap??
View attachment 944199
Re: pre-filter pressure convo with MrMCar:
Did you measure unfiltered pressure, and if so at cross section are you measuring? Maybe I'm wrong but it comes across that you are presenting a hypothesis without data, and then telling someone else who has a different hypothesis that only they must supply the evidence?
In the OFH's flow pathway, the cross sectional area seems to be constantly varying. For dynamic internal flow, when cross sectional area decreases, fluid velocity increases and the static component of pressure (the component our sensors/switches measure) decreases...and vice versa. Higher measurement point also = less pressure. To state that pre-filter pressure is higher than post-filter pressure for a constantly varying pipe is like apples to oranges, unless you know you are comparing a pre-filter flow point that is equal in vertical position and cross sectional area to the oil pressure switch's location.
IF you were measuring two comparable points, yes, you'd probably have some loss in static pressure due to friction. I think there have been bench tests that use horizontal piping of constant diameter to demonstrate that with filters. But for complex plumbing like our OFH, you'd have to know velocity, height, areas, etc to establish total mechanical flow energy (potential energy via static pressure + kinetic energy via dynamic pressure) and how much is lost to friction/heating. If your point is that the oil loses mechanical energy passing through a filter, yes that's true, but it's different than static pressure alone.
Side note, according to Bentley manual table "Oil Pressure", it varies at the switch location from 7 psi (once warm) at idle to 59 psi at higher RPMs. PSI vs RPM was taken by another user here:
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Oil pressure light flickers on at idle
I know this topic has been discussed before, but I have never seen a definitive solution. Problem: Red oil pressure light flickers on at idle, when engine is fully warmed up. This only happens when transmission is in Drive and car is stopped (idle speed 550 RPM). Light immediately goes out...www.e46fanatics.com
This seems to imply that the bolt bottom O-ring is to prevent the oil in the filter drain back. I think this O-ring is for different reason.Now that the filter was mounted upside down, drain-back and constantly having to prime the filter housing on every engine start after sitting for 10 minutes or more would make short life for the engine, owing to the 1 to 2 second delay of getting the oil where it needed to be.
On the aforementioned engine, a metal cap is used with a long bolt and sealing ring at the bottom.
The O-ring is for empty the oil (cleaned and dirty) out of the "can" when replacing the filter. It was not designed to avoid the drain back during normal shut off the engine, as the check valve after the pump should take care the drain back issue.On the aforementioned engine, a metal cap is used with a long bolt and sealing ring at the bottom. If you remove the bolt/O Ring and filter. Then let it drainback. Reinstall the bolt ONLY (not removing the O Ring) and fill the OFH, oil will remain in the housing. It's the O ring or Rings that hold the canister full.
I know that without the O-ring on the rod the oil will drain, because when they designed the new upside down filter can, they added the drain hole to empty the oil can (the old filter can was removed off the engine to empty the oil, or remove the bolt to drain the oil), and so they also added the O-ring to block out the drain hole in normal usage.Try something. Replace your oil filter, leave the 2 small O Rings off. Then start your car after 2 days.
I did, and the rod bottom hole goes through the whole length to the top end to the unfiltered oil. So the section between the 2 o-rings is connected to pressurized dirty oil, and this cannot be connected to drain tube 11.I need to blow into the rod hole![]()
This proves that the section D between the O-rings is not connected to the drain tube 11 as shown in the patent drawing.I did, and the rod bottom hole goes through the whole length to the top end to the unfiltered oil. So the section between the 2 o-rings is connected to pressurized dirty oil, and this cannot be connected to drain tube 11.