does anyone know to what level of filteration the standard oil filter on a 617 or 603 engine filters to? the manual also mentions that the oil filteration system completes some fine filtering at the filter through the filter housing stem. for the life of me i cant see how it does fine filtering except maybe its the slower flow of oil thru the small stem holes.
can anyone help here, thanks
larry perkins

I don't know about the 603, but the 617 filter cartridge contains two filters, one full-flow which traps large particles (like any other full-flow filter), and a bypass section that traps fine particles. The full-flow section outputs a lot of oil to the bearings, the bypass outputs a very small amount of oil back to the sump.

I believe a standard oil filter for a 617 filters down to about 25 microns. The bypass section on the OEM filters should filter down to about 4 microns.

I, too, am curious at how the stem filters anything.

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Ralph

1985 300D Turbo, CA model
248,650 miles and counting...

i have to believe that there must be filter material inside the stem of the oil filter cap, as i read the instruction for oil change mb suggest the cap assy be replaced if there is no flow thru the stem.
anyone got a spare that could be cut to see if there is cotton,hemp,et there?
larry perkins

I doesn't. But it does provide for the return flow for the oil that has been filtered by the bypass portion of the oil filter. So if the pipe is blocked, the bypass section of the oil filter is out of action.

tang, would you have any ideas how the device does the fine filtering of your oil?
larry perkins

could the theory be to pass the oil back to the pan without exposing it to the moving parts,hot gases and call that a fine filtering process?
i just built a pre lube system that allows all moving parts to recieve oil prior to cranking the engine and as an improvement for cleaning the oil and cooling the oil for turbo longivity i want to add a cycle after engine shut down and was trying to understand if there was in fact a fine filter function.
thanks for any insight.
larry perkins

Oil flows from the outside of the bypass filter to the inside. Then it enters the "stem" through the small hole near the cap, then flows down the stem and 'returns.' The stem itself does no filtering, it just provides the return flow for the oil that has passed through the bypass filter.

How does this system of yours work? Do tell...

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Ralph

1985 300D Turbo, CA model
248,650 miles and counting...

go to search, type in larry perkins, i did a write up on the oil system under new product survey.
larry perkins

I'm resurrecting this thread because I have a question.

Does the oil destined for the engine (which comes from the non-bypass portion) not run through the stem? I'm thinking it must.

If it does, how is it that oil from the bypass section goes one place and the oil from the other section goes to another place?

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Ralph

1985 300D Turbo, CA model
248,650 miles and counting...

This will tell you all you want to know starting on page 4:

mb.braingears.com/123_DISK2/program/Engine/617/18-005.pdf

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Jackson

1984 300d 223k
1994 Jeep Cherokee 2.5L 88k

"She may not look like much, but she's got it where it counts, kid. I've added some special modifications myself." -- Han Solo

"Would it help if I got out and pushed?" -- Princess Leia

No.