What's inside that MANN oil filter? Taking it to bits...
 

Prompted by a discussion in the "OIL FILTERS: which one to buy????" thread, I have totally disassembled a MANN oil filter for the 616/7 engines.

Here is the cadaver. As you will notice, there is a dent on the side that made me feel less guilty about hacking the thing to bits.

http://www.peachparts.com/shopforum/...filter-006.jpg

I first tried to get the top off by assaulting it with lots of sharp tools -- lots of them.

http://www.peachparts.com/shopforum/...filter-007.jpg

Realizing that I was getting nowhere, I tried a can opener as per OM617Yota. That worked like a charm.

http://www.peachparts.com/shopforum/...filter-009.jpg

That pretty white thing on top is basically paper -- when you take it off, you find cotton that looks like it's been in a fight.

http://www.peachparts.com/shopforum/...filter-010.jpg

So at least it was well packed. This is all the junk that came out of the filter. Yeesh!

http://www.peachparts.com/shopforum/...filter-012.jpg

Here is the inside of the filter. Both the inside tower and the outside shell are covered in some sort of thin cotton.

http://www.peachparts.com/shopforum/...filter-013.jpg

The outside cloth is held on by the pressed flange at the top of the filter.

http://www.peachparts.com/shopforum/...filter-016.jpg

On the inside cloth, a piece of tape at the top of the filter was holding the cloth on. Neither cloth was sealed in any way at the bottom.

http://www.peachparts.com/shopforum/...filter-017.jpg

This rubber grommet is coming out just because I can take it out.

http://www.peachparts.com/shopforum/...filter-018.jpg

This pressed flange needs to be unfurled to get the outer wall of the filter off. It's a pain to get started -- I used a flathead screwdriver to start unfurling it -- but once you have it going, you can use pliers to unfurl it the rest of the way. This was painful at first, but once I developed a method for doing it, it went swimmingly.

http://www.peachparts.com/shopforum/...filter-020.jpg

Completely unfurled.

http://www.peachparts.com/shopforum/...filter-022.jpg

I ended up having to hack at the top where the seam for the outside cylinder is joined so that I could unfurl the side, too.

http://www.peachparts.com/shopforum/...filter-024.jpg

The side seam was easily unfurled with a small flathead.

http://www.peachparts.com/shopforum/...filter-024.jpg

http://www.peachparts.com/shopforum/...filter-026.jpg

Once the side seam is unfurled, the cylinder pretty much peels right off.

http://www.peachparts.com/shopforum/...filter-027.jpg

It's off.

http://www.peachparts.com/shopforum/...filter-029.jpg

The center tower is held on by five spot welds at the base. Here it is coming out...

http://www.peachparts.com/shopforum/...filter-031.jpg

Here's what's left.

http://www.peachparts.com/shopforum/...filter-032.jpg

I started to peel the top off. Some sort of rubberized compound is holding the top onto the rest of the assembly and also holding the fins in place.

http://www.peachparts.com/shopforum/...filter-033.jpg

Now it's almost off.

http://www.peachparts.com/shopforum/...filter-033.jpg

Now it's off.

http://www.peachparts.com/shopforum/...filter-038.jpg

I stopped here, but it is interesting to note that the compuond here on the bottom is a tan color while the compound on top is gray.

http://www.peachparts.com/shopforum/...filter-040.jpg

Here is everything we took out.

http://www.peachparts.com/shopforum/...filter-041.jpg

All in all, only one blister and one cut (all for the sake of science, of course). Not bad!

I'll post an explanation as to how the filter works later, but duty calls and I must step away from the laptop for a little bit...

Is the Mann filter different from the Gurl filter?

Dan

Thanks for taking the time and trouble to do this.
I had no idea that some sort of cotton material was in the filters.

Looks well built.

now we need someone to tear into a purolator, and a fram and compare them

Meh. Not terribly impressed -- as OM617Yota's photos more clearly show this thing has dirt in it. Filtering dirt with dirt seems pointless, especially if the thing isn't fully sealed, which it isn't at the bottom of the large cylinder. Here is OM617Yota's description of what's in the filter. He has better pictures of the junk.
If someone gets them for me, I'll do it :D.

the wix filter is super easy to examine... there's only the pleats.

Maybe I'll take apart a MANN fuel filter apart tomorrow.

[EDIT]Looked at it tonight and it looks too tough for me to take it apart. The metal is much thicker. However, upon inspection, it appears that it is filled with that orange cartridge, so at least it's not filled with dirty cotton.[/EDIT]

As others pointed out in the other thread, some bypass filters use dirt and saw dust in bypass filters for million mile trucks. Mann is by far the best stock filter you can buy for your engine.

My Pics from the Purolator L43056 I got from PepBoys 4 years or so ago are in one of the 3 large Oil fiter Threads.

The Filter was made in India and the Cotton Gin that was inside was not terribly firmly packed.

It had more of the typical Trash in it and the Cotton was poorer than the other that people have cut apart.

Worse the central inside Tube is not sealed on the Bottom like the Onter makes it is just the Metal Tube sitting on the Metal Bottom.
The STP Filter that Autozone was selling was also made in India and it looked to be the same Filter.

But, they could have change how the make them since then.

I hope you can see the pics in post #278
http://www.peachparts.com/shopforum/diesel-discussion/104768-oil-filters-one-buy-19.html#post2119904

OK, so I don't know how much -- if any -- difference clean cotton makes, but if it's available at a CHEAPER price than the MANN and isn't deficient in filtration otherwise... why go with the dirty? Furthermore, why call it the the best? That seems strange.

The cotton junk probably does a better job of trapping and holding a larger capacity of contaminants than a pleated filter. The Mann filter has a pleated paper section, the sotton I assume for coarse filtering, the pleated paper for finer filtering.

Might be the case, but then why don't we have the filtration capabilities somewhere. I'd buy it if I could find what it's rated to filter. I will grant them that they PACKED that sucker.

I'm going to fire off an e-mail to them and see if I have better luck than Diesel911.

I don't know why that struck me as so funny, but thanks for that. :D

the pleats are for coarse filtering of the main oil flow, the cotton only gets oil through the tiny bypass orifice. the cotton packing absorbs soot, and lets the oil pass through. it's at very low pressure, and very low volume, but it filters much finer than the paper.