re. diesel black oil. To add to Davids info, in a diesel soot is a major by product of combustion and the collection of it is the primary cause of the oil turning black in a diesel. The oil has additives in it to keep it suspended as opposed to allowing it to collect on the internals. Std diesel oil filters will not remove all of it so new oil will blacken soon after use. My 3 cyl Tier 3 Kubota diesel will blacken new oil within a couple hrs of use and has since it was new.
re.216, I estimate the bottom end of my 49 216 to have 113K miles on it and it has had a bypass filter on it since new. I know this as i have a copy of the original invoice and it was added as a $10.85 + $4 in labor dealer option.
New oil will blacken within a couple hrs of use on it. I believe it's due to it being run with non detergent oil for most of it's life and I've been running detergent oil it for the last 13K miles. The blowby/byproducts have collected on all the internals and the detergent oil is cleaning off what it can. The bypass oil filter doesn't seem to effect the blackening of the oil in any manner.
