When I take my oil sample for analysis, I'd like to minimize the amount of oil I'm replacing so I get a better idea of how well the original oil's holding up over the entire interval. If I'm changing my oil filter at the same time (it'll be over a year on my car at that point), can I just dump the oil from the filter into the sample bottle? Any contaminants should be trapped on the anti-drainback side, right?
The other option would be to take a filler tube sample first, & then change my filter & dump the old filter's oil back into the engine. That's a lot more time & effort than the first option, & I'm not sure the readings will be any different. (Of course, if there's not enough oil in the center of the filter to fill a sample bottle 3/4 full, then I'm gonna hafta use a tube anyway.)
On one car, the filter's mounted vertically so I get a full filter of oil when I take it off. On the other car, the filter's mounted horizontally so I'd hafta crack it loose & catch what dribbles out.
not a good way to do that, especially the sideways mounted one as it will pickup debre from the side of the motor.
The best way if all you want to do to sample is use a vampire pump such as amsoil sells...
Here are a few other tips on taking oil samples...
Taking oil samples
Is there any reason not to take the sample out of an oil filter where the open end faces up? I want to do it this way due to the value of my oil. I can spin my oil filter off without losing a drop and with the aid of a really big syringe I would be able to get the sample in one suck from the centre of the filter. I think this would be better than the dipstick method because the dipstick hole probably has grunge in it.
I'd do this after a drive ofcourse.