Is there a "best" place to draw your oil sample?

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Hi Folks,

First post here for me. Should a sample be taken from:

1- oil drain plug
2- line TO the bypass filter
3- Line FROM the bypass filter.

Seems like you would get different results and I am wondering if there is a recommeded location.

Thanks!
100 Proof
 
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Couple of schools of thought here.

For a typical engine, especially without a bypass, the drain plug is the ony resonable option. But, you have offered that there are alternatives available to you.

Sampling before the bypass filter would be a good indication of the engine actually shedding it's metals, and what solubles are present. This is presuming that the oil goes straight to the bypass filter from the pump, and is not pre-filtered by the full flow filter. Not that this is undesireable, but it just is not a true "used oil condition" scenario.

Sampling after the bypass would be a good indication of how well the filtration is performing, and what the condition of the oil is that is SUPPLIED back to the engine.

Hey - do all of us BITOGers a favor. Why don't you pull a few UOA's at all three points and post the results. WE LOVE TO LIVE VICARIOUSLY THOURGH THE EXPERIMENTS OF OTHERS!!!
 
Put 1/3rd in the bottle from each place, then shake.

(D-Roc is psychic!)
 
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Assuming you take the sample when oil is hot, I don't believe you will get substantially different results. Simplest thing is to install a Fumoto valve and take the sample from that. You could even take it when the engine's running if you wanted to get "in-service" results.
 
Hi,
with my vehicles, my client's vehicles and especially when evaluating lubricants for Oil Companies I always followed this sequence;

1 - Lubricant must be above 60C and engine recently shut down
2 - Sample via dipstick tube using a suction extractor with bottle attached. First extraction goes into a "waste" bottle
Second extraction becomes the actual sample

This was followed even at OC point

I hope this helps
Regards
 
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D-Roc was right; I was being sarcastic; but only somewhat.

I don't expect anyone to pay for 3 samples of the same oil.

100Proof - I wasn't poking fun at you, I was poking fun at all us BITOGers. Seriously, we do live for the joy of over analyzing anything lube related.

Your post wasn't totally clear. Do you have the abiltiy to pull a sample as the engine is still running, like some tap port? Or, were you just asking if it was ok to break the line somewhere? If you can, I'd always prefer taking a "live" sample as an engine runs, slowly drawing off the fluid. You'll get a much better cross section of the whole system that way.

For me, I just pull out the drain plug, let about 20 seconds of oil run out into the drain pan, then stick the bottle under the flow, thereby getting the "middle" section of what setteled in the pan. Not the best, but as long as I'm consistent in the samples, the averages will norm out over time.

BTW - welcome. You'll either laugh and enjoy this site each day, or it'll make you pull your hair out ...
 
Even though I have a bypass and can pull a sample from the return I still always pull from the fumoto drain valve. After I pull into the driveway I drain a qt out into a clean container and then take my sample. I return the qt of oil back to the valve cover.
 
Thanks Guys-

I do have a Fumoto valve on this engine already. I do not yet have a bypass system installed. Having said that, I'm a bit AR about how my installs go and how they look afterwards. As I was doing my planning to install one, I was wondering if I needed to provide for a line "tap" in the plumbing somewhere or just pull from the pan. I would prefer to pull from the pan in order to leave my plumbing, and its integrity, intact.

Thanks again!

100 Proof
 
Originally Posted By: dnewton3
BTW - welcome. You'll either laugh and enjoy this site each day, or it'll make you pull your hair out ...


Thanks. I've been lurking here for a while to learn a few things. I expect I'll enjoy the site a lot. Having said that, if I post about oil types or brands, or different by-pass filter set-ups, I'll be sure to keep my NOMEX suit handy!

I do have one other question about UOA. If I want detaled particle count data, where is the best place to send my sample? Is there a particular way to specify that with the order?

100 Proof
 
I can tell you that any spectral analysis (UOA) typically will report elements in the 1-5um range; anthing above that will not be picked up by a traditional spectral UOA.

Perhaps someone with good/bad experience can chime in here about the particle count analysis. I've not had one done.
 
Originally Posted By: 100Proof
If I want detaled particle count data, where is the best place to send my sample?

100 Proof

The most accurate PC method available is the laser beam particle count. There are two labs that I know of that use that method and they are Butler Cat Labs and Polaris Labs.

Flip side of the coin is this....diesels are sometimes hard to do the laser beam method due to the soot in the oil. The dark soot maxes out the machine and it can't get a reading due to the soot laden oil.
 
For about 15 USD I put a valve between the sending unit. Engine hot at idle I run about 5 oz into a clean flush container. This will clear the copper tube. I then fill my sample bottle, close and shake well. I dump the first sample into the flush container. Be sure its clean so all the flush oil can be returned to sump. I then fill my sample bottle. I just have a 1/8" copper tube attached to the petcock valve. Its bent into a faucet, this is very consistent, there is no waste, no mess.
I use Polaris labs and am very satisfied - you can get a free first at this link. http://www.polarislabs1.com/test-kit.htm

Link to my UOA's http://forums.tdiclub.com/showthread.php?t=190958
 
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Something to consider is to try and use the same technique each time.

This time at least YOUR results will be consistent, I don't think either technique will change more than 5% assuming you do each correctly.
 
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