Oil flow and oil filter housing valve question

[Localjoh]

During my last oil change, I removed the filter and was greeted by a spring and pan type pin that shot out of the filter housing. It usually sits inside the filter cage and would act as a spring-actuated valve of some sort. I found the spring and the plastic piece with the cup. It has the very bottom pieces broken which would normally secure it in the cage, however with the filter on there it has nowhere to go and still open when pressed upon from the top.

Now my confusion. According to the flow diagrams, I found the flow of the filter works by filtering fluid from the inside to the outside, however, it appears this valve would only work to push from the outside in, furthermore, the flow diagrams show the valve and spring action working opposite of how it seems to function in reality.

Can anybody actually confirm the flow of oil and what the intended function of this valve is, is it needed (I suspect it's there for a reason, just can't visualize what function it would have if the flow is truly from the inside out). Lastly, I'm tempted to not replace the filter housing as the valve appears to still work fine with the retention piece broken of that little valve mechanism as the filter holds it and prevents it from going anywhere and the spring pushes on from the other side, although I would need to be careful with further oil filter replacement.

Any insight is appreciated.

Oil flow diagrams in the links.



https://photos.app.goo.gl/7dpwRpoUBSL21seN6

https://photos.app.goo.gl/UynxzZuLxk7hBYNr5

[Zolli]

I *think* it’s a check valve / overflow valve thing, like a fail safe.

[Localjoh]

I was able to source a whole new housing locally from wrecker. I will feel better knowing it's exactly how it was intended to be.

However i'm still curious on the flow direction and why the referenced diagrams appear to have the valve spring loaded, releasing pressure from the inside to the outside when in actuality the valve would let oil back to inside, or at least that's how I'm seeing it.

[Atomic Avant]

Its a check valve from the inner part of the oil filter.

If your filter becomes clogged or oil pressure is to high for some reason the check valve will let oil pass around the filter rather then through it.

Its a safety measure, dirty oil is better then no oil.

[Localjoh]

That concept makes sense, but that would mean the oil flow would have to be from the outside filter to the ii inside for the valve to function in that manner. Check out the marked up diagram I drew in (excuse my sloppy phone photo markup ability) how the valve is actually installed in red.

https://photos.app.goo.gl/uXcQKRrhv5peYWUe9

[Atomic Avant]

That concept makes sense, but that would mean the oil flow would have to be from the outside filter to the ii inside for the valve to function in that manner. Check out the marked up diagram I drew in (excuse my sloppy phone photo markup ability) how the valve is actually installed in red.

https://photos.app.goo.gl/uXcQKRrhv5peYWUe9

is there a chance that your valve is installed backwards?

[Atomic Avant]

That concept makes sense, but that would mean the oil flow would have to be from the outside filter to the ii inside for the valve to function in that manner. Check out the marked up diagram I drew in (excuse my sloppy phone photo markup ability) how the valve is actually installed in red.

https://photos.app.goo.gl/uXcQKRrhv5peYWUe9

Ok, so I just took my cap off and refreshed myself with the oil filter housing.

The little spring and plastic pin that faces upwards inside the house is there to apply tenson to the oil filter cap during removal and install. Why? not sure, probably German engineering. If you look inside the cap you can see a recess that the plastic pin fits into. I am guessing that yours was broken and came off when you remove the filter.

The check valve we have been talking about is inside the black tube in the filter housing (you can't see it). Oil does flow from inside the filter to the outside and drain down around it.

Now is that ball and spring are there for an dirty filter or to stop oil from draining back to the pan when the car is off I am not sure.

[Rol-co]

This is what I found

The red arrow is a valve what opens if the filter cap is removed, to drain the oil.

[Localjoh]

That all lines up now. Looks like this is pretty common area of failure.

[inflowmini]

So, I've been doing oil changes on the 4.2 for a while and for the first time ever, that spring (the arrow pointing to it) popped out and broke. So is the conclusion that this valve lets the oil drain? Does it drain to the bottom of the oil pan or does it work its way down to through the engine and then the oil pan? Also, is it possible to buy this spring without purchasing the whole housing? My issue right now is that I did an oil change because of low oil pressure. So I first changed the oil pressure sensor then changed the oil, car started fine but it's still low on oil pressure. I wonder if this valve is the culprit.

And yes, I checked for oil leaks, the timing has been done, and I did all the basic checks but I rather fix this valve than to change the oil pump. Anybody has ideas if this valve can cause low oil pressure?

[Rol-co]

So, I've been doing oil changes on the 4.2 for a while and for the first time ever, that spring (the arrow pointing to it) popped out and broke. So is the conclusion that this valve lets the oil drain? Does it drain to the bottom of the oil pan or does it work its way down to through the engine and then the oil pan? Also, is it possible to buy this spring without purchasing the whole housing? My issue right now is that I did an oil change because of low oil pressure. So I first changed the oil pressure sensor then changed the oil, car started fine but it's still low on oil pressure. I wonder if this valve is the culprit.

And yes, I checked for oil leaks, the timing has been done, and I did all the basic checks but I rather fix this valve than to change the oil pump. Anybody has ideas if this valve can cause low oil pressure?

Don't think anyone can tell you, but the engines are not well known for failing oil pumps, have one laying around here but its pretty straightforward. Low pressure can be a lot of things, at my engine there was leakage because of the solenoid housing not tightened but can be bearings worn out, oil (over)pressure valve.

I had 4 bar pressure when cold, 1,2 when hot and both at idle when audi oil pressure light is not working. (Only at drive)

[shokwav09]

it's a pressure-regulated system. so if you overfill you don't blow some of your seals. the little plastic piece stabilizes the filter so it doesn't spin lessening the flow rate. if it created a vortex the gerbals inside could drown trying to pump the oil. if pressure is too low the ECU isolates the part of the path through sensors it's having problems with so the gerbals don't dry out. What bugs me is why Audi has AN ports that are in line with the housing. what were audis intentions for that? Because if it's meant for extra cooling i'd do it.

[neilpaku]

I'm adding a pre-oiler to my car and wanted an easier connection option than the oil pressure sender location. There's a large hex plug on the front of the valley cover that connects directly to the oil filter. I want to use that plug to connect the pre-oiler.
In reading this thread, it looked like the consensus was that the filter flow was from inside to out, which if true, would be opposite to most (every?) filters I've ever seen. So I did some analysis on my engine and my conclusion is the opposite for the following reasons:
- the oil pump outlet is via a tube to the upper pan, through the side-mounted oil cooler and back into the upper pan where it then connects to the block at the corner nearest the water pump
- the oil then flows up to the valley cover via a check valve. That check valve only permits flow in this direction, from the block into the valley cover
- the valley cover gallery with the large hex plug then travels to the driver's side inlet of the oil filter housing which directs the oil to the outside of the filter element
- oil flows through the element and back down the center of the housing and out to the oil filter outlet on the passenger side
- oil then flows into the main block gallery which feeds the crank and has outlets to various other places
- those places include the piston cooling sprays via a check valve, and the timing assembly and camshafts also via a check valve. This check valve can only permit flow from the main gallery through teh check valve and thence to the camshafts/timing chain adjusters via smaller galleries in the block that head up to the cylinder heads and rear timing cover

If all that is correct, then pre-oiling at that large plug is ideal because:
- the check valve in the block prevents the pre-oil running back to the oil pump
- the pre-oil will have to go through the filter, which is a good thing
- I don't have to mess with the oil pressure sender which is not easy to get to, relatively speaking

With that in mind, I had my guy make up a replacement plug, tapped for an M24x1.5 banjo which has a 5/8 JIC spigot which will connect to the pre-oiler which I plan to install behind the grill with an appropriate length of hose.

IMG_0926.jpg

[Rol-co]

@neilpaku

Why you want a pre-oiler? What would be the point? Seen some accusump a few years back, that is what you mean with pre-oiler?

[neilpaku]

I want it to make the guides last longer than the last run on a set of guides which was 90k miles. Yes on the Accusump.

[Rol-co]

I want it to make the guides last longer than the last run on a set of guides which was 90k miles. Yes on the Accusump.

Don't think it would prevent but more a disguise for the problem, keep the oil pump pickup clean, checkvalves fresh, oil filter housing with working valves and you will have zero chain slap and should work easily 150k miles or 15 years with original parts. Using 0w40.

[dimetime]

Don't think it would prevent but more a disguise for the problem, keep the oil pump pickup clean, checkvalves fresh, oil filter housing with working valves and you will have zero chain slap and should work easily 150k miles or 15 years with original parts. Using 0w40.

0w-40!? Ive been on 5w-40 MolyGen, suggestions for oil brand?

[neilpaku]

Rol-co, "should" is not the same as "does" unfortunately : ) None of those things you suggested (which I already knew from the rebuild at 85k anyway) were sufficient for 150k. It got 90k. The fact is that the design is sub-optimal, so I'm anticipating that pre-pressurizing the tensioners will increase longevity but only time will tell.

[Rol-co]

Rol-co, "should" is not the same as "does" unfortunately : ) None of those things you suggested (which I already knew from the rebuild at 85k anyway) were sufficient for 150k. It got 90k. The fact is that the design is sub-optimal, so I'm anticipating that pre-pressurizing the tensioners will increase longevity but only time will tell.

Only things sure in life is death and pay taxes

@dimetime
Not realy, you can use any A brand. I'm using kroon oil for 35k km's but castrol, total will do fine also.

[shokwav09]

the guides will last over 180k when oil is regularly changed. maybe longer. DO NOT RUN anything other than reccommened oil. i used castrol and it slumped performance.
plus they use detergents and conditioners in eu vehicles and oils designed for better lubrication.
if you can set a secondary filter{external} up thatll help some. coolers are the best solution. the cooler the better.
ive read audi techs even state the r8 dry sump is equivalent to most v8 wet sump sytems. they just used one in r8's for lowering the engine and center of gravity.
theres oil coolers on the market already that delete the oem and allow adding extra dissapators. im working on designing titanium plates myself from my rs5 platform.

and rol-co. dont forget heartache and herpes. lol

[Rol-co]

the guides will last over 180k when oil is regularly changed. maybe longer. DO NOT RUN anything other than reccommened oil. i used castrol and it slumped performance.

Recommended is castrol and 5W30 longlife, but also the 0W40 or 5W40, ALL specialists who are repairing these engines give a 0W40 or 5w40 advise, some say 5W30 kill tensoners.

plus they use detergents and conditioners in eu vehicles and oils designed for better lubrication.

And we have aliens here who pis in it, a bit of bs talk, oil is no different you need to be aware for fake ones, there are fake castrol and other A brands on the market.

if you can set a secondary filter{external} up thatll help some. coolers are the best solution. the cooler the better.
ive read audi techs even state the r8 dry sump is equivalent to most v8 wet sump sytems.
they just used one in r8's for lowering the engine and center of gravity.

What this got the do with the old dinosaur V8 in our car? Dry sump performed the same, great!

theres oil coolers on the market already that delete the oem and allow adding extra dissapators. im working on designing titanium plates myself from my rs5 platform.

Ah there it is, much newer cars with much thinner oil, do not compare these fsi with the dinosaur S4

and rol-co. dont forget heartache and herpes. lol

Ive read Toyota drivers don't have them but still pay taxes and dying.

[shokwav09]

run castrol vs some molygen then tell me your herpes isnt cured.

[Rol-co]

run castrol vs some molygen then tell me your herpes isnt cured.

Liqui

https://pim.liqui-moly.de/pdf/en_US/liqui/58/P001758

Castrol

https://msdspds.castrol.com/bpglis/FusionPDS.nsf/Files/71A33DFDE780B8EE8025858B0062238A/$File/wepp-bqutgg.pdf


Both vW502.00 507.00 standard

Both shouting the same slogans 😉😁


I'm using this one for a long time.
https://advice.kroon-oil.com/en/info...5-l-can-EN.pdf

[shokwav09]

i know. im speaking from experience. liqui or moly kills the comp.{in audi} especially with performance filters. itll boil down to preferences regardless. in my srt4's i used royal purple. still dominated. it varies.im not clowning castrol though. castrol is reknown.

good women drive toyotas.


viscousity is still better at higher temps with liqui... just sayin

[neilpaku]

Anyhoo, back to the pre-oiler - this is how I'm planning to connect it - I can't remember how much room there is in front here so I'll need to get the engine reinstalled with the cool etc. installed to confirm, but if anyone can weigh in with some photos of standard clearance, that would be helpful

IMG_0939.jpg

[Rol-co]

Anyhoo, back to the pre-oiler - this is how I'm planning to connect it - I can't remember how much room there is in front here so I'll need to get the engine reinstalled with the cool etc. installed to confirm, but if anyone can weigh in with some photos of standard clearance, that would be helpful

IMG_0939.jpg

This will fit, but you need to mount the lines before the front, even at service position it might be difficult to get the lines tightened.

[shokwav09]

howre you gonna clear your coolant manifold?

[neilpaku]

I'll have to test fit a couple of times. If it does fit, I'll probably still need to install and uninstall it a couple of times to get the lines made up.