Originally Posted by GregW / Oregon
Not sure, but shouldn't that drain by gravity? If not, not too much to do about it.
My E39 M5 had a oil-water heat-exchanger to cool the oil (and warm it when it was cold) and based on switching oils and doing UOA's I concluded that there was 1 liter of oil in the cooler circuit that just didn't drain on a 6.5 liter oil change.
It took unique components of an "old" oil about two changes to "decay" to around zero after changing to a "new" oil. They dropped to about 15% of the original PPM measure on the first change, 2% on the second, then after that they were undetectable.
It didn't seem to matter as far as performance was concerned. On that basis the 100cc in the filter body is just noise when you're changing from used TWS to new TWS.
And, if I didn't say it already, THANKS! for posting the DIY pix - I will do mine next April at about 8,000 miles/1 year on the car.