Oil Extractor not extracting. Why?

[DFWdude]

Winterized the boat yesterday, and tried to change the oil with little success.

8.1 VP GXi
Ran engine for 15min to warm oil.
Dip stick shows safe level of oil.

95023326-D646-40A6-93E5-44D1B8192F23.jpeg

Extractor tube inserted same length as dip stick, and it only slurps air.
Tried extractor in full jug of fresh oil, no issues.


Any ideas why it cant pull oil out of the big block?

[billk2632]

Interesting if you are sure the tube is getting down to the bottom of the oil pan. Also, could the tube have a hole in it that is covered when you tested it, but not when it is in the dipstick tube? Would be like drying to drink from a straw with a hole in it. I have one of these vacuum pumps and it has worked fine for years, but last year I bought a pump that screws on the top of the dipstick - seems to work much better and is cleaner - pump the oil straight into containers to discard.

[DFWdude]

I tried it with my finger on the end of the tube, and it held a vacuum w/o the sucking air noise.

[Krob1114]

Did you try lifting it up just a bit to make sure it was getting a seal on the bottom?

[Krob1114]

. I have one of these vacuum pumps and it has worked fine for years, but last year I bought a pump that screws on the top of the dipstick - seems to work much better and is cleaner - pump the oil straight into containers to discard.

What brand do you suggest?

[billk2632]

I got a Jabsco, but there are several brands that look to be the same pump.

[DFWdude]

Did you try lifting it up just a bit to make sure it was getting a seal on the bottom?

I did

[Kate]

"Dip stick shows safe level of oil."

Checked before or after you ran the engine? If before, did you wait after running the engine for the oil to return to the pan?)

"Extractor tube inserted same length as dip stick . . ."

When you pulled the tube out, was there oil on the end of it?

Is the boat level? (If not, your jug test will mislead you. It's also not a good test because you're extracting clean, fresh oil versus old, dirty oil.)

Could be that the tube is bending at the bottom of the pan.

Is the pump self-priming? If not, it can suck air during extraction.

Did you open the fill cap?

[DFWdude]

Checked after i ran the engine.
Yes, extractor tube had oil on the exterior portion.
Boat as level as it could be. Maybe off a degree or two from true level.
The dip stick tube wont allow a weird bend. It stops at a hard 90 degree

09BC4589-2858-4757-870E-A1C04D38772D.jpeg

Please note that I loosened the fitting at the pan just to ensure oil was there and leaked out. Hence oil in the bilge.
Oil fill cap was removed.
Using this pump;
OEMTOOLS 24937 6 Quarts (1.5 Gallon) Pneumatic and Manual Fluid Extractor, Manual and Pneumatic Oil Extractor, Fluid Vacuum Extractor, Vacuum Evacuator https://a.co/d/hdo2Aqq

[bruceb58]

Use a pump that threads into the garden hose at the top of the dipstick tube. No need at all to send an even smaller tube down the dipstick hole.

You may already have a fitting that came with your pump to do this. If not, I am sure you can make something with what you have.

[DFWdude]

6642A0C1-EC47-4287-AFD3-C277904BEA27.png

Brilliant.I’ll give it a shot. Thanks!

[DEcosse]

Use a pump that threads into the garden hose at the top of the dipstick tube. No need at all to send an even smaller tube down the dipstick hole

If I'm interpreting correctly what you're saying (i.e. no line down through the dip tube, just connected at the top), how does that get the oil from the sump below the end of the dipstick tube?

I have an 8.1 and my EWK extractor (Pneumatic type) works just fine
There are really 3 possible causes
Insufficient vacuum
A leak that is sucking from air vs the oil (whether that be on the extraction hose line or within the main canister system)
Hose not in the oil

Recognize it is going to want to pull from path of least resistance.

You have the filler cap off, right? Want to make sure that it can breathe as you pull oil out!
Not sure about your model but be sure you don't have a valve or cap open that you want closed during the evac process.
The operating procedures that come with these things (regardless of brand) is woeful.

On my compressed air system, when I first got it I thought that you kept the air flowing (this is how my Mityvac Brake Fluid extractor works);
Not only is that less efficient, it is also incredibly noisy as compressor runs all the time!
But I found the best technique is to cycle the valves:
Keep extraction valve closed then open the airflow and chamber valves and watch tank gauge get to 'max' vac reading;
Close chamber valve and air valve; (if you do nothing else at this point it should hold that vacuum reading for an extended time if your system is 'tight')
Open the extraction line valve.
Let it pump until the vac level on the gauge depletes to low level - then recycle through the valve sequence again to re-establish max vac.

Edit - looking at your model you linked, it seems it does not have a vac gauge and no valve on either the extraction line or the venturi connection to the tank. So it's unclear to me how you establish (and can isolate) a high level of vacuum on that model. (insert head sctratcing emoji here)

[DFWdude]

Being an ME, this is driving me flipping mad.

The extractor works in multiple other fluids, so it should work in the boat engine.
The extractor works via pneumatic or manual pumping, on other fluids.
The dip stick shows a “safe” level of oil, so there should be oil to extract.
The extractor is inserted the exact same length as the dip stick, and also moved in and out.
The oil fill cap was removed.

And yet the extractor cant pull jack squat out.

Using the threaded fitting would remove the extractor’s line as a variable, but since said line works elsewhere it should work here too.

Possible issues going on;
Dip stick is wrong and I have almost no oil in the pan
My boat is cursed
Dip stick line could be blocked
Any others?

[DEcosse]

Is it possible you are 'bottoming out' the hose, so it's sealing itself to the bottom of the pan? Try pulling up an inch or so when hit 'bottom' just to see if that helps
It sounds like maybe the hose is either in too far (either 'sealing' against bottom or curling back up above the level) or not in far enough.
Being an ME (you, not me - I'm an EE ) I'm pretty sure you measured the length of hose you are inserting vs the length of the dipstick to know just how far you're going in .......

[DEcosse]

I just thought of another quick test - remember trick of putting a straw in a drink, then sealing the opening with your finger and you pull out the straw and you have a straw full of liquid?
Put your hose (alone, not connected to pump) down the tube to the length that equates to your dipstick length;
seal the upper end of the hose with your thumb, then pull hose out;
you should have oil in the bottom of hose same as level indicated on your dipstick