I found "silt-sediment" at the bottom of my used oil bottle!

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Mar 14, 2003
Nothern USA
If the stuff is coarse enough to feel gritty, it may be material deposited on the bottom of the oil pan, and flushed out with the oil. Think about sandpaper. 325 mesh grit is about 29 microns. A 10 or 20 micron filter will let anything much smaller than that through. What weight oil are you using? Nobody seems to have good figures on how much the bypass either in the filter or engine opens. When the bypass is open, there is no limit on what bypasses the filter. The heavier the oil, the less of it goes through the filter. A highly efficient filter may also bypass more.
Also depends on how long you let the oil drain and where you did it. I know here in Oklahoma on a dusty day, if I let the oil drain for about an hour or so, and I'm doing this outside, some of that dust will get into the oil and show up at the bottom of the jug when I drain it.
There will always be debris on the dirty side of the filter and below it (in the oil pan). The job of the filter is to keep the debris on that dirty side, and let the filtered oil go through..the oil then picks up new contaminates throughout the engine and dumps back in the oil pan...and starts the whole process over again. The benefit of changing the oil while it is hot is that the debris is suspended in the oil in the oil pan and more of it drains out with the oil. If the oil is changed after sitting for a while/overnight some of the debris settles out and ends up staying in the oil pan...consequently mixing in with the new oil fill. [No no] I can see the point about Oklahoma dust flying in too...isn't that where the tornado movies are made? [LOL!]
Could just be road dust that collects in your drain pan. Do you drain into a pan then bottle it? What happens to the pan between drains, do you leave it on a shelf in your garage? Is it an open pan or one of those funnel-topped closed deals? This is used oil we're talking about, right? Do you wipe down/wash out the drain pan or leave it gooey? I use a cheapie funnel-topped closed pan, and never wipe it down. It's naaasty, but so what? [I dont know]
Is this normal? It took a few days to settle but it is easy to see...kind of like a small finger sized smudge at the bottom. Does this mean my "quality" oil filters are not doing there job? Or is the oil was in fact doing its job by holding tat stuff in suspension so long? If in fact these were contaminants do you think a micron oil filter bypass system woudl stop this? *lol* the sediment although minute bothers me [Smile]
That's why I store my oil bottles upside-down, so the undissloved particles pour out easily into my engine.
I am running my own "zealot" 3-bottle/cycle of Auto Cycle process. This oil came from the second bottle treatment phase. Chevron 10W40 + 1 Bottle Auto RX + 1,510 miles + SuperTech (to be exact) *lol* The previous auto-rx phase had a grit too.. Sample was taken hot directly from oil pan drain bolt. This leads me to believe that perhaps this is juts normal skank getting removed at the oil change? Questions: A)Would it be overkill for me to drop the oil pan and have it professionally cleaned? Would I need to order a gasket set + RTV sealer...or both to do proper service? B)Will a spotless oil pan contribute to the oil staying cleaner longer? Thanks-
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