Another question on oil over fill

[jtm3]

Quick backstory – 2001 VP, 7.4L Gi PEFS, Where I store it, they drain the oil, change the filter when they winterize the block in Oct and then add the fresh oil in the spring. This last Saturday, load up with fresh oil (15W/50 Syn) – 5 quarts. I tend to work with the owner (friend) he poured the 5 quarts in, started on muffs, checked everything, launched – test run, oil pressure good, holds temp on a plane (all good). Bring it across the lake to slip. In the past I have had to add a quart to keep it in the safe range (6 total). I pretty much check the dipstick every time I go out. Check it this time and it was way past full! I know these dipsticks can be finicky, so I warm up the engine let it sit 10 minutes check it again still high. Tried letting it sit overnight, no change.

Went back, warmed up and sucked out 2 quarts and let sit 10 minutes checked it, and it was back in the safe range. So I am wondering last fall if the boat wasn’t level or the pump lost prime could there have been 3 quarts or so still in there? Prior to pouring the new oil in the dipstick showed dry. Thinking of doing a complete change to start fresh. Could there be anything else I am missing? Thanks.

 

[Lou C]

I have to tell you in 48 years of changing my own oil I have never heard of a shop draining the oil in the fall and not refilling until the spring! Who does that! The only time a shop might to this is if an engine was test run and then had to be shipped somewhere for an installation. I would advise asking them for their rational for doing it this way, because I can’t think of a reasonable one other than to get you to come back to them again!
If this is the type of dipstick where the tube goes to the bottom of the pan yes they can give odd readings until you get the hang of how they work; oil must be able to climb up the tube for it to read accurately. So here’s what happens. Right after you run it warm air in the tube prevents the lovel from rising all the way, but if you pull the stick out and leave it out for a minute or 2 the level will stabilize at the correct level. When it sits overnight the reverse happens where the column of air contracts and pulls oil up the tube and then it reads too high (like a qt) but if you pull the stick out and wait it will stabilize same way. So in both situations you pull the stick wait a few min and it will read more accurately.

 

[jtm3]

Thanks Lou, he has been doing boat maintenance at his yard for 40 years and just retired from being the head mechanic of the towns school bus as well as a merchant marine, but I don’t understand it either, but it is what it is. I give him my preferred oil in the fall (I store the boat in his shed for the winter) so it would be easy enough to add it. Everything runs fine and pressure is good 40 at idle and close to 60 while under load.

But yes it is one of those tubes, that I have learned the tricks to get it to read accurately. I’m just anxious that this could be sign of a larger issue. At this point I’m inclined to do a complete oil change for piece of mind. Unless I should be looking for something else.

 

[Lou C]

The only other thing that will create an overfill is water in the oil, that can cause the oil level to rise quite a bit, and the milky oil does not always show on the dipstick right away. I’d take off the oil fill cap and see what it looks like inside there...if it’s nice clean oil no worries, if it looks a bit like mayo then you have something to figure out.

 

[Scott Danforth]

Fuel in oil will also raise level

Also, you need oil in the sump to keep the oil pump primed and corrosion at bay.

Suggest you may want to look for a new mechanic, or do the work yourself