What's inside an oil filter (pic heavy)

[s2_wot]

Following a thread on audisrs about small metallic particles floating around in oil I decided to open a filter to see what's inside.

The filter here is off my s6 and was replaced with an OEM item.



Cut / peeled the top off it with much difficulty. I used a snips so I wouldn't make any more metal dust.



1st part out the top is this rubber diaphragm:



2nd part out the top is this part with a spring on the underside:







Here you can see the spring in it's compressed position:



And here it is in the relaxed state, the spring itself is quite weak. I think it forms a non return valve, preventing unfiltered oil from returning.



Filter removed from housing:



At the bottom of the filter is another spring. This time it's a much stiffer item. I wondered about it's inclusion. it could be there to ensure a tight assembly taking manufacturing tolerences into account and to allow the thing to be assembled. But I think it's there to allow oil pressure to transfer fully around the filter.




With the base of the filter raised off the lowest point of the housing there's also space for sludge to gather.



The bottom of the filter is covered in tiny metal particles and thick oil.



Then i cut the filter media away to reveal the core:





The filter media:



It rolls out to 1950mm and is 80mm high:



Close up of the dirty side:



I've washed out the contents of the filter housing into a bowl filled with parts cleaner. I've also put half of the filter media in there with a couple of magnets. Over the next week I'll give it a stir every now and again. Hopefully I'll be able to seperate the metal bits just to see exactly how many are there.

[speeding-g60]

we do this every oil change on the racecar.

but we use the actual tool for the job, its much easier.

[s2_wot]

we do this every oil change on the racecar.

but we use the actual tool for the job, its much easier.

After seeing the gunk that was on the filter media I can well understand that. Can you predict / diagnose failure from that procedure or why do you do it?

Sweet looking instrument that, I'm not planning on opening too many more tho'

[mouse]

When I did some work experience with some aircraft mechanics many years ago they always opened up the filters to check if there were any metal pieces trapped in the filter.

[Nuvo]

Part two of Shane's incredible car component autopsies. Collect the series to gain a valuable insight into the internal construction and workings of a variety of parts. Apply for your subscription today to avoid disappointment.

Nice work Shane, you evidently have an inquisitive mind.

[macspring]

Shane,

Excellent work and photos, was keen to know these two myself. Maybe a hydraulic tappet next ?

I understand these can be serviced rather than just replaced ?

A radiator could also be a contender for opening ?

Kind regards.

[Billman]

Excellent work and photos, was keen to know these two myself. Maybe a hydraulic tappet next ?

There was a repost from a VW forum about these long time ago here in the forum.

[pixsaudisex2]

good work

Here is the tappet one..

http://www.s2forum.com/forum/showthread.php?t=41038

[Jas11n]

There was a repost from a VW forum about these long time ago here in the forum.

>>>>> LINKY

[johne]

At the bottom of the filter is another spring. This time it's a much stiffer item. I wondered about it's inclusion. it could be there to ensure a tight assembly taking manufacturing tolerences into account and to allow the thing to be assembled. But I think it's there to allow oil pressure to transfer fully around the filter.

The stiffer spring is there to hold the filter in place until and if the point comes when the filter is so blocked that oil cant pass through the filter medium at which point the spring will allow the filter to lift and pass unfiltered oil through that way ensuring that the filter can never cut off the oil supply to the engine.

John

[andy10v]

Thanks again, keep up the good work.

What did you ask for at Christmas? A chop saw?

[s2_wot]

The stiffer spring is there to hold the filter in place until and if the point comes when the filter is so blocked that oil cant pass through the filter medium at which point the spring will allow the filter to lift and pass unfiltered oil through that way ensuring that the filter can never cut off the oil supply to the engine.

John

Ahha, excellent, I'll have to put some weight on it, it's pretty stiff

Thanks again, keep up the good work.

What did you ask for at Christmas? A chop saw?

I asked for money so I could go drinking on a saturday night, santa fail.


What will I cut up next weekend, time will tell.

[Le S2 Audi]

Another interesting Thread!!

[Boghopper]

I would be interested to see inside the genuine filter, and compare the two.

Pete

[EspenW]

I would be interested to see inside the genuine filter, and compare the two.

Pete

That is a Mahle/Knecht filter. They produce most of the oil filters that come in the boxes marked "Audi" as well. Should be the same exact filter.