Oil Extraction - Half Oil Changes

[UNC201]

How do you guys drain out partial oil in your sump to *recharge* your oil.

For UOA, I use the hand pump as the bottle screws right in, clean tube down the oil stick, etc.

What if you just wanted to drain some oil, and dump fresh oil in - half of the sump qty. The bolt would be messy trying to get it back on while the oil is pouring out.

The extractor is nice and while you can clean the outer tube that fits on the extractor....what about the remnant, residual oil that is on the inside of the tube.....Just thinking outloud....

 

[02zx9r]

I normally undo the oil drain plug, let it drain all the old oil out, put the drain plug back in, and then put new "fresh" oil in.

 

[UNC201]

That's what I do for a full OCI....

What if it's half a drain or quarter of the sump qty drain

 

[GROUCHO MARX]

That Fram Sure Drain allows me to put a 5 qt plastic bottle under the car and dump the oil right into it.

In the Sport Trac, I can do this while the truck is parked at the curb if I choose to.

 

[02zx9r]

Not really sure, never attempted to do that. Have not had a reason too. Good luck with your quest

 

[JHZR2]

I dont get the problem...

Why not buy a proper extractor that has a decent holding capacity, like the topsider or equivalent, available from Tractor supply company and marine stores??? Some are 12V operated, so move fluid fast and work really well.

If you want to use your UOA device, youll be doing a lot of pumping.

Is the issue about the film of oil on the tube a concern??? If youre worried about the old film contaminating your sump, do the math. consider the volume of a few micron thick layer, on the inner circumference of the tube, by its length. A few milliliters at best. Start the entry of the tube under vacuum and this is a non-issue.

If youre worried about your UOA device being contaminated, then just pull a sample or half a sample, discard or return to the sump, then pull a real sample. This way anything on the walls will not be present in your UOA.

Am I just not getting your question???

JMH

 

[UNC201]

I'm using a Pela for the mini-extraction. Not the sample pump.

Just thinking outloud on how it could possibly skew a used oil analysis if I drew from the oil and *recharged-refreshed* the oil.

 

[JHZR2]

AAAh, you mean actual UOA results numbers...

Well the first interval UOA would be normal. the second one would theoretically be a baseline of the average of the concentrations of the metals at the first UOA, plus those inherently in the recharge oil, plus whatever wear/depletion occurred that interval. The next one would be the same, but the averages leverage off of the last numbers. You could easily calculate the theoretical skew in excel.

JMH