Filter seal lodged in case??? 190D (601)
 

I'm scratching my head on this one. I would love it, if someone could put my mind at ease.

Well performing an oil & filter change on my 84 190D, after removing the stem and filter, I found a seal in the "eng case standpipe" (as in the tube that receives the filter stem, and the bottom of the filter. ) I was looking down in the the filter housing and noticed what looked to be a dislodged o-ring at the bottom of this tube, very hard to see, I took a long 90 deg scribe hook and removed it. I could not figure out if it was supposed to be there or not, it almost looked like it belonged there, just below the point where the oil passage makes a 90deg turn, sealing the stem off, where the ID necks down in the eng case.

My theory: Well the more I look at it, it appears to be a filter seal/grommet, as it is the same ID as the upper and middle filter seal/grommets in the filter body. One side is radiused, and it's shape is deformed (heat??), it appears to me, to be like something that might come out of one of the cheaper filters, rather then having a square shoulder on both sides like the all the OEM filters I have seen. I can only surmise that the P.O. somehow knocked it out of an oil filter, while pushing the stem thru the filter. (The stem looks fine, both o-rings present and accounted for.)

I will try to post a jpg of the suspect seal, next to one of the smaller filter seals, might be a bit out of focus though.

TIA, Mack

cc, Tech & Diesel forums.