Where's the oil?

Mark Maulden · Nov 25, 2015

Is your dipstick flexible? Maybe your rigid plastic extractor tube is hitting something that your dipstick is able to bypass...my extractor tube is similar to a flexible dipstick. If nothing constrains it, it snaps straight but it is flexible..

JohnVTX · Nov 26, 2015

There will be a quart in the filter

Rich Stidger · Nov 26, 2015

Measure the length of the extractor tube that goes into the dipstick and then gauge on the outside if the length is correct. Sometimes the tube will hit the bottom of the oil pan and then curl up so that it doesn't suck at the bottom. I use the same extractor myself. The other thing you can do is to cut the bottom of the extractor tube at a 45 degree angle. That won't account for the missing 2 quarts, but it will help to get the oil out. And johnVTX is correct, there will be some oil in the filter depending upon how the filter is mounted. If the filter is attached on the side or possibly with the screw side down, most of the oil should drain back to the pan.

Also, are you sure that the crankcase was full before you started? Maybe you were down a quart to start?

woodster · Nov 26, 2015

Will some one tell me how you can find a qt of oil in a filter that has no more space inside of 1/2 to 1 pint of volume

Rick I · Nov 26, 2015

5 quarts sounds like a lot for that engine (2QM20). Are you sure that's what the manual says? I would think the capacity is about 2 quarts.

Harlan · Nov 26, 2015

The quart in the filter is when you accidentally spill it while removing.

Davidasailor26 · Nov 26, 2015

Rick I said:
5 quarts sounds like a lot for that engine (2QM20). Are you sure that's what the manual says? I would think the capacity is about 2 quarts.

That's what I thought too given that our 3YM30 only lists as taking 3 quarts. But I found a copy of the manual for the 2qm20 online and sure enough it says 5.1 liters (5.3 quarts).

DougM · Nov 26, 2015

My 2GM20 manual indicates an oil capacity of 2 liters which is about 2.2 quarts. No way would it hold more than that an perhaps a bit less due tonth incline of the engine

Bill Roosa · Nov 26, 2015

If the engine is at an angle you may not have been filling her up to 5 qt in the first place if you filled to the "full" mark on the dipstick. The angle also casues the oil to pool in the rear of the oil pan where the suction tube may not be reaching it. If the tube goes forward or to the side that oil will get left in the pan.
When you refill be sure to add 5 qt and then check the dipstick after running the engine to fill the oil filter. That is the correct "full" mark not the one on the dipstick calibrated for a level mounted engine.

Bill Roosa · Nov 26, 2015

The 5 qt amount was meant to be the correct facitory recommendation. I don't know what the correct ammount is as I don't have the manual.

Davidasailor26 · Nov 26, 2015

Rich Stidger said:
Also, are you sure that the crankcase was full before you started? Maybe you were down a quart to start?

I'll bet you're on to something there. The service manual at http://www.dieselpartseurope.com/we..._discontinued/service/2qm20_servicemanual.pdf says that the total capacity is 5.1 L, but it also says the effective capacity is 3.3L. Effective capacity is the amount that you need to add to get from the min line to the max line on the dipstick, so if the OP was 1/3rd from min to max then there was probably about 3 quarts in it.

Siamese · Nov 26, 2015

If only a lot more sailboats were sold, then we might expect the engines for them would be better suited to their environment. Nowhere is this lack of compatibility more noticeable than when performing an oil change. The ideal sailboat engine would have an accessible drain plug located at the extreme aft end of the motor where the oil would drain regardless of the angle of the engine. And then, the exiting oil would be channeled into a trough and into a pan for disposal.

Or, at the very least, there would be a more appropriate place to insert a suction tube, so that the tube would have a fairly straight shot at reaching the lowest point of the oil pan.

My Catalina 28 with a Universal MP25xp is a great example of poor engineering. A fairly large amount of oil is left behind with each extraction because of the angle of the engine and the shape of the oil pan.

Bottom line, you just do the best you can. The best tip I can offer the OP is to get that oil as hot as possible before attempting to extract it. I suppose my engine will eventually come up to full operating temperature while idling in the slip, but I if I'm serious about getting the job done, I take it out of the slip and run her at 80% of max rpm until it comes up to around 160 degrees. Get 'er back in the slip, and start suckin' oil. I'll still never get it all out, but at least I know I'm getting as much as I can.

seadaddler · Nov 26, 2015

Has happen to me once but since that time I let the engine really run until it is
really good and hot and I use a 12 volt extractor and it can run dry no impeller type and let it run extra time for sure.
They stop putting drain plugs in the bottom many years ago and some put a permanent power drain but I worry about a bad leak happening.
I use Rotella 15-45 and change the oil often and oil to me is cheap.
Nick

Benny17441 · Nov 26, 2015

The proof is in the pudding. Do not see anything wrong with the current protocol of partially removing used engine oil by pumping out the dipstick. Sure a good portion of the used oil remains behind but it is rejuvenated by the addition of new oil. The reason I'm fine with this is that these small engines have proved they can run for thousands of hours thus validating the practice. Our crankcase oil turns black rather quickly and that comes from combustion residues. The filter removes the larger particles and just leaves the very small which really do not cause any significant harm. This black seemingly dirty oil is not really the cause for engine wear but it is the breakdown of oil viscosity due to heat and friction that may do most of the damage. As a large portion of used oil is replaced the viscosity is largely restored to the remaining oil. This method has worked so well that the engine manufacturers have mostly eliminated drain plugs as boat manufacturers stopped allowing any clearance for their use.

RoyS · Nov 27, 2015

Does this not beg the question; Why was the dip stick not located at the rear of the engine?

Siamese · Nov 27, 2015

Benny17441 said:
The proof is in the pudding. Do not see anything wrong with the current protocol of partially removing used engine oil by pumping out the dipstick. Sure a good portion of the used oil remains behind but it is rejuvenated by the addition of new oil. The reason I'm fine with this is that these small engines have proved they can run for thousands of hours thus validating the practice. Our crankcase oil turns black rather quickly and that comes from combustion residues. The filter removes the larger particles and just leaves the very small which really do not cause any significant harm. This black seemingly dirty oil is not really the cause for engine wear but it is the breakdown of oil viscosity due to heat and friction that may do most of the damage. As a large portion of used oil is replaced the viscosity is largely restored to the remaining oil. This method has worked so well that the engine manufacturers have mostly eliminated drain plugs as boat manufacturers stopped allowing any clearance for their use.

Yeah, gotta agree, the pudding's where the proof is. These engines run and run despite our not being able to get all the oil out.

Stu Jackson · Nov 27, 2015

RoyS said:
Why was the dip stick not located at the rear of the engine?

...because most likely the engine was originally designed for use in a TRACTOR, not a boat.

Our M25 has a hose on the bottom of the oil pan, which makes oil changes pretty easy. I just got the right fittings and connect it up to a hand pump. People who still do the dipstick-trick simply haven't gone the next step, but, heck, if it works for them, that's fine. But it's slower since the dipstick is a lot narrower than the 1/4" hose at the bottom of my oil pan.

weinie · Nov 27, 2015

The right pump definitely helps too. Mainesail turned me on to the moeller oil extractor pump which made winterizing a breeze this year.

markwbird · Nov 27, 2015

I do not think 5 qts is correct. My 3gm30f holds 3.5. Also, the proof is in the putting. There is no pudding involved.