When to check engine oil level (filter drainback?)

[ChickenPinz]

I'm finding that the engine oil level creeps up over time after shutdown, and am suspecting that it's due to the oil draining slowly out of the filter into the crankcase.

Do others have that same experience? My filter is Mann W940/29.

[rmel]

Yes. They drain back S L O W L Y

There is a non-return check valve, 0.12 BAR to open, but since these
filters are mounted laterally, they will leak back over the course of a
day or two. That's been my experience.

[gael12]

I forgot how to do it

[ChickenPinz]

Interestingly, I don't see this on aircraft engines with horizontal filters. Or my Toyota with inverted filter above the engine.

[rmel]

It's what I have observed -- and apparently you as well.

Both for the Mann and Mahle filters.

Wait a bit, measure the Oil, do it again 12 to 24 hours later and
you got a considerable increase in level. Way more than lub residing
on the innards. Can only be coming from one source -- Filter.

Some filters don't have a reverse check valve. They would leak back faster.

[Hotzenplotz]

I'm finding that the engine oil level creeps up over time after shutdown, and am suspecting that it's due to the oil draining slowly out of the filter into the crankcase.

Do others have that same experience? My filter is Mann W940/29.

Mate, you use the wrong filter ...

The W940/29 does not have the return valve. Use the W940/5 instead, and the phenomenon will disappear !

[rmel]

Interesting. For many years here in the US, the reference filters have been the Mann 940/29
and the equivalent Mahle OC 54. I use both interchangeably. It does appear neither have
return check valves but as you pointed out the /5 does (as well as W 940).

So the drain back taking many hours is even more perplexing. Still has to be coming from
the filter though.

Assuming the reverse valve is effective, given the position, that should result in establishing
flow quicker and reduced start-up wear.

OK Albert, now you have opened a huge can or worms For those using Mann/Mahle
filters what PN# are you using? I'm curious.

[ChickenPinz]

And Mann filter confirms that the W940/5 is correct, and W940/29 is not for Pinzgauer per their application data here:
https://catalog.mann-filter.com/NA/eng/ ... /W%20940~5
https://catalog.mann-filter.com/NA/eng/ ... W%20940~29

Capture.JPG (25.6 KiB) Viewed 5907 times

Seems like the Goatwerks site needs updating: https://www.goatwerks.com/interchangelist.htm since it calls out the W940/29 version and that's what I went from originally. FWIW, SAV sells the /5.

[rmel]

And EI have sold the /29 but now the Mahle OC 54 which is compatible with the /29

Neither have ADB valves. You can inspect your filter for the presence of a check valve.
Look at the base and if you see black or red rubber under the peripheral drain holes,
it's valved. Black is Nitrile, Red Silicone -- and superior. Even with a valve, mounted in
the horizontal position the filter will drain down to just below the central tube.
Presumably there's enough negative pressure with standing oil down to the sump to
hold that valve in check.

I do have a /5 in the 712, I don't recall where I picked that up. But available on
Amazon. I believe they all have the same flow rate and Bar setting for the bypass valve.
So at this point the /5 should be a better choice as Albert has pointed out.

[Hotzenplotz]

All

I do my maintenance based upon the Austrian army Pinzgauer manuaL edition 1998.
They list W940/5 and W940/18 as applicable oil filters.

[ChickenPinz]

Looks like the /5 and /18 are the same, except that the /5 has the hex nut on the end whereas the /18 just has knurling.

Time to toss out the /29 filters.

How do we get the Goatwerks site updated to show the /5 over the /29 option?

[Hotzenplotz]

an email to info@goatwerks.com should be enough

Just did it

[ChickenPinz]

For reference, here's what the 940/29 filter looks like:

IMG_20200606_184506 (Large).jpg (332.75 KiB) Viewed 5755 times

And here's what the 940/5 looks like:

IMG_20200608_142011 (Large).jpg (246.42 KiB) Viewed 5755 times