Drawing an oil sample

[Johnstra]

Anybody able to draw an oil sample through the dipstick tube? I want to draw a sample without removing the drain plug. I have a little siphon, but the hose won't go all the way into the pan through the dipstick tube. It's blocked by something.

-john

 

[amsoilman]

cut the tube on a 45 degree angle, and it will most likely go in.



Wayne

amsoilman

 

[WNowlan]

I would add that to make sure the tub does not pickup debris on the sides of the dip stick tube. This will alter the results. You should also measure the length of the dip stick tube and this should be the depth you take the sample. Make sure the engine is a operating temp as well.

 

[nickleinonen]

put a needle valve on a length of hose [grease gun or hydraulic hose] that is long enough to reach from the port on the filterhead and can reach the engine oil fill cap. with the engine running, open the oil fill cap and open up your needle valve to get the oil flowing and let it run into the oil fill for a bit to make sure you get a good sample, then fill your sample containter, then close off your needle valve and tie wrap it out of the way somewhere away from the exhaust manifold... will take a little time to set it up for first time, but once in place, it'll be real easy to get samples later

 

[Johnstra]

DUUUUHHHH...



Sometimes my brilliance surprises me, but most of the time (like right now) I'm kicking myself in the a$$ for being so stupid.



I HAVE A BYPASS FILTER THAT RETURNS VIA THE FILLER CAP!



DUUUUUHHHHH!!

 

[DLeno]

this is one of those situations where its more important to be consistent and repeatable than it is to choose a particular collection method. That said I have to say Nick's method probably lends itself the best to repeatability! to interpret the numbers themselves, it would be important to understand if the collected oil is post filter or pre-filter, and what that might mean in terms of the concentration of contaminants on each side of the filter, and (if the sample is post filter) the filtration efficiency and performance of the element.



Since in my experiments it is important to drop the oil at the same time as the sample, I used the drained oil method at oil change time. I first clean the oil pan well, especially around the drain plug, always ending with a new shop towel wetted with new oil. I back out the plug some and clean again. When I finally drop the plug, I let the oil drain for a few seconds before collecting the sample from the stream. the sample should come from the middle, not the end or the begnining of the drain.

 

[nickleinonen]

if your changing the oil at the same time as sampling it, are you not defeating the purpose of sampling it? other than to see if you have a coolent leak or excessive silicon in the oil, the sampling shows you if the oil is good to go or not, for extended drain intervals...

 

[ROCKJEEP]

I have the genos drain kit and all I do is screw on the hose and fill the container and then take the drain hose back off. never spill a drop. Well there was that time where I ran over the container with the creeper I was on and made a mess, but pther than that it works every time

 

[tae73]

I second rockjeeps way of doing, thats the same way I do. Sure is nice not make a mess all over yourself and all your tools.

 

[DLeno]

if your changing the oil at the same time as sampling it, are you not defeating the purpose of sampling it? other than to see if you have a coolent leak or excessive silicon in the oil, the sampling shows you if the oil is good to go or not, for extended drain intervals...

yea, depends on your goals. I'm studying the effect of air filters on silica levels and engine wear indicators of iron and chrome. Even for extended drain interval studies, while I agree its better to sample without changing, you can accomplish the same thing over time with successive changes, the argument being that trends are the important thing, not the absolute numbers. that is, one oil change and many samples is not by itself a reliable indicator to establish oil drain interval. Of course, if your'e out to extend the drain interval, then a good way in my opinion would be to do the single change/many samples thing to start out, and then change and sample at the regular intervals using the newly established drain interval -- as validation.