Best Practices for taking oil samples

[btanchors]

Hi all,

I'm about to take the first samples for UOA on the transmission and engine from my 2003 GS430. I'm using a bellows-type container connected to a plastic tube that goes down the dipstick.

When I've done this in the past, I extract the sample with the engine hot, but shut down. I'm wondering if I would get a more representative sample if I extracted the sample with the engine running. What I have in mind is to insert only the length of tubing that equals the length of the dipstick, perhaps slightly less. This would ensure that the end of the tube isn't just sucking junk from the bottom of the pan. I'm thinking with the engine running, the oil would be circulating and therefore I would be more likely to get a representative sample. What do you think?

 

[olympic]

I wouldn't do it. Your tube could get caught up in the crankshaft. Just take the sample immediately after a long drive and you'll get a good representative sample.

 

[Al]

Your goal is to extract the oil from about the middle of the sump. Thats just goodsampling practice. Problem is to determine where the end of the dip stick tube ends. I guess that the best you can do in this case is to look at the full mark and if say the engine holds two quarts you go down the tube one more length equal to the distance from "L" to "H". If the tube goes down further than that-so be it. I would not have the engine running.

That's just my opinion. Hopefully there are better answers.

 

[Redneck53]

I think that the sampling method depends on the lab you use. I will be using WearCheck and they recommend that you sample part way through the drain and not thru the dipstick tube. (just followin' orders !!)