Getting All Oil Out of M25 - How?

I'm sure this has been addressed before but I could not find the exact answer. The M25 in out E32 is installed at a 13 degree down angle. When changing oil I can only get a little over 3 quarts out thru the oil pan drain plug suction hose. The rated capacity is 4 quarts. I am thinking there could be up to a quart remaining in aft part of the oil pan. Has anyone a method to get this last quart of oil out when changing oil? One fellow on our dock recognizes the problem and just drains, refills, warms up and redrains to dilute the remaining quart and says that has to be good enough. I am kind of hoping there is a more eloquent method.

Try dipstick port

I get nearly the full gallon by pumping warmed up oil through the dipstick hole.

Chris,
Do you insert a suction tube inside the dip stick tube or just connect to the top? If you insert a tube, about how far? Any special insertion technique?
Thanks - Jerry

Actually I do both. My E34 M25XP came with a oil pump out system that was a hose connected to the drain plug. This, because of the mentioned angle, left the approx. quart or so. I switched to pumping, actually sucking, the oil out via the dip stick pipe. I use one of those systems that creates a vacuum in a can where you then insert a tube into the pan and release th clip and the vacuum sucks the oil out. This is obviously a small plastic tube and I play around with it, moving it in and out and side to side when the suction breaks and manage to get almost all the oil out. I then pour in another quart or so, turn the engine over a turn or two without starting it and vacuum that oil out. That does a pretty good job, but the new oil is still black when I check it.

Having never seen how the dipstick is fitted into the oil pan I was not sure just how to pump it out. Have heard where some manufacturers provide for oil suctioning by just connecting to the dip stick tube (no insertion tube needed). If I ever get my oil pan off (unlikely, I hope) I think I will fabricate something for 100% oil suctioning. Thanks everybody for the suggestions.

Do not be overly concerned about getting every last drop of oil from your engine when you drain it. Its not a problem for the new oil to be slightly contaminated as this will happen anyway the next time you start it. It would be simpler to reduce the oil change interval by 25% and spend time on other things.

RT

FWIW I use an insertion tube and poke it around (especially near the end of the process) to get the used oil out. What Rob said makes sense to me but according to my measurements I definitely get more than 75% out.

Cheers,

Draining oil from a Yanmar 2 or 3GM.

All, For those of you with a Yanmar 2 or 3GM engine, consider doing what I did with my 3GMF. I drilled out the center of the starboard, aft doughnut foot on the bottom of the crankcase and fitted the hole with a 1/2" brass street ell that I screwed a bronze barb into. I have a Reverso oil pump attached to the hose from that fitting and now simply flip a switch to drain the oil into an empty 1-gallon oil bottle. By simply removing the dump hose and inserting it into a new bottle of oil and flipping the switch the other way, I can refill the engine, no fuss, no muss. I catch oil from the filter using a rag and a 2-liter soda bottle with the top cut off and get most of the spill. The cut off bottle top fits perfectly into the fill cap in the rocker arm cover of the Yanmar like the soda companies and Yanmar got together to agree on compatible sizes. That top make a great funnel for those who add oil the conventional way. Regards, Glyn Judson, E31 hull #55, Marina del Rey, CA

Answered to my own question

I feel stupid. My cute 2 1/2 gallon vacuum bottle (previously evacuated to 25 in-Hg) that I use to suck out the oil, starts sucking air before I get all the oil out. Now, I suck till I get air, secure, wait a minute, then suck again. Doing this a couple of times gets almost all the oil out. At least now I can refill this M25 as per specifications with 4 quarts and the dipstick shows about 1/4 inch above "Full". Close enough. All the responses to my original post were good stuff and I appreciate them all. Got me thinking for sure. This one is done!

That's great Jerry but be very carefull overfilling. Always use the dipstick to measure. Never rely on the specs. Engine angles are different, you really don't get every bit of oil out, etc. Having the oil too high in the pan can prevent the connecting rods from properly spashing oil onto the cylinder walls. I would take a little out.