What exactly is your oil filter removing?

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Elkins45

Elkins45

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Has anyone cut open a used oil filter to see if it’s actually catching anything? I’m going to saw open a couple of the next ones I remove. As well sealed as most new engines are I wonder if the oil filter isn’t just primarily an insurance policy.
 
Oil filters catch metals and crud. Oil filters greatly prolong the life of the engine.and the oil change interval.
The air filter is the most important filter the engine has.
 
Search this forum for posts by member "car51". He has compiled enough cut-open filters to educate anyone on what a filter removes from the engine. He's also a veteran, so IMHO this board owes him two sincere "Thank You For Your Service(s), Mr. Car51!"
 
Mine's removing particles of 20microns or larger, and some smaller.

To be fair, long ago engines didn't have oil filters...and they didn't last.
 
If you want to know what it catches you'll have to remove the media and perform a solvent wash while capturing the particles. You'd at least get a weight this way and maybe be able to distinguish carbon or non-metallic particles from metallic ones. Obtaining an overall view of the composition of the particles would require an acid digestion and ICP analysis, I don't know if Blackstone is capable of doing that (we used fuming nitric acid, very dangerous stuff). If you want to know the size and composition of individual particles that would take something like SEM/EDX to determine.

Just a filter wash and capture might be interesting, along with looking at it with a magnifying glass or microscope if you have one. Another crude analysis would be to use a strong magnet and see what ferrous particles you can pick up out of the particulate.
 
As far as stuff that's visible to the naked eye or with a simple magnifier, I typically find a few tiny black (carbon?) particles, and only occasionally a tiny shiny (metal) particle or two on my used media. I don't know about the quantity or composition of microscopic stuff, but I know there's not enough of it to change the appearance of the media surface much, and not enough to restrict air flow through the used filter much (after I soak out most of the oil).

The original factory-installed filter of my Mazda had one large metal shaving stuck part-way through one of the entrance holes of the base plate.
 
No one here has ever cut open an oil filter, that is just crazy talk...
28.gif
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Oil filters do - oil filter stuff...
 
Originally Posted By: JLTD
Mine's removing particles of 20microns or larger, and some smaller.

To be fair, long ago engines didn't have oil filters...and they didn't last.


They lasted as long as the engines with filters at the time. SBC V8 '55 no filter boss, added in '56. You'd get 100K Miles out of either of them. 120 was an outer.
 
This is my Ridgelines break-in oil filter Honda wanted me to leave in for 10K.


It's removing the white substance whatever it may be pretty well.
Every pleat has something in it.

It's not removing very fine metal particles very well, nor does any full flow filter really.
The dark bands are ferrous particles that went round and round till the magnet caught them.

I'm glad I used it.

Uncle Dave


 
Last edited:
Originally Posted By: Johnny2Bad
They lasted as long as the engines with filters at the time. SBC V8 '55 no filter boss, added in '56. You'd get 100K Miles out of either of them. 120 was an outer.

Oh for the days of smoking cars. People would try to figure out which side of their V8 smoked - though I don't suppose it mattered very much.

Engine rebuilds (or at least valve and ring jobs) were once fairly common. Engines simply wore out. They must be pretty rare nowadays (with the notable exception of engines with having some sort of defect).
 
Originally Posted By: ecotourist
Originally Posted By: Johnny2Bad
They lasted as long as the engines with filters at the time. SBC V8 '55 no filter boss, added in '56. You'd get 100K Miles out of either of them. 120 was an outer.

Oh for the days of smoking cars. People would try to figure out which side of their V8 smoked - though I don't suppose it mattered very much.

Engine rebuilds (or at least valve and ring jobs) were once fairly common. Engines simply wore out. They must be pretty rare nowadays (with the notable exception of engines with having some sort of defect).


Cars don't wear out a lot anymore unless totally neglected. They just don't have a lot of load and as a consequence, they have little wear.

Hard working mid-size and 1/2 ton trucks Trucks maintained with OEM stuff and mid-grade oils and fluids wear out all the time.
Top ends go first around 1-150K and 10 years then at 15 the rings clap out.

I see this more than most guys because I have had clients with the same boat for 20-30 years that have worn out 2-3 trucks in that time towing the same routes.

UD
 
Last edited:
Originally Posted By: JLTD
Mine's removing particles of 20microns or larger, and some smaller.

To be fair, long ago engines didn't have oil filters...and they didn't last.

Yep, and they only had a few hundred mile OCI's. Oil filters definitely do a lot to keep engines going!
 
Originally Posted By: JLTD
... To be fair, long ago engines didn't have oil filters...and they didn't last.
To the extent that's true, it might have less to do with oil filters than with other changes, including improvements in air filters, paving of most formerly gravel roads, PVC systems, elimination of leaded gasoline, etc.
 
Originally Posted By: CR94
Originally Posted By: JLTD
... To be fair, long ago engines didn't have oil filters...and they didn't last.
To the extent that's true, it might have less to do with oil filters than with other changes, including improvements in air filters, paving of most formerly gravel roads, PVC systems, elimination of leaded gasoline, etc.
+1
 
Originally Posted By: Leo99
It's like the lint trap in your dryer.



A lint filter does more then most oil filters!

Normal wear particles are way smaller then 10 microns,
most filter filter 20 microns and larger and not all of them!! LOL

I've cut open a lot of filters from good engines with an oil filter cutter, it leaves no
bits that would contaminate the filter, I found very little! On a bad engine expect more!
 
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