Yanmar 4JH oil change puzzle

[bytownboy]

Happy owner of Yanmar 4JH-HT(B)E, but puzzled every time I change oil. The manual clearly states the oil capacity to be 6.5 litres. I carefully suck every drop I can from the crankcase thru the dipstick pipe, remove the oil filter and replace with a new (empty) one and then add fresh oil. Today I added less than 5 litres (about 1/2 litre removed from new 5 litre jug). Started engine to circulate fresh oil and fill oil filter and ran it for about ten minutes. Shut down engine, wait a few minutes and check oil only to once again find the oil level above top line on dipstick????

This is consistent with all my other oil changes. Any others out there getting same results? Should I just suck some oil out and quit being so anal?

[delmarrey]

At what angle is the motor sitting? My yanmar manual gives the specs with the motor sitting level. When it's tilted back, it'll show more oil then it's actual recommended level. My motor sits at 10 degrees so I remarked the dipstick to show full at its proper capacity.

It's really odd in the installation manual, that it requires a level installation. But most boat motors are normally at an angle. I basically ignored that part. But did have to deal with the oil level situation as above.

And btw diesels need that large oil capacity.

[bytownboy]

Thanks for the reply Delmarrey. Not sure how level my engine is, I haven't noticed that it angles towards the stern but I will check tomorrow with a level when I'm on the boat.

Cheers Doug

[delmarrey]

You can use the heat exchanger to gauge from. It's parallel with the motor.

[pwmullins]

Have the same engine for over 25 years. I get the same results. Still working fine. I have nothing more to add to help you.

[IdoraKeeper]

I have the same engine. The exact same thing happens. When re filling the oil after a change, I monitor the level carefully as the fill progresses. Depending on the filter you install, you may need to add a pint or so to get it up to the line with the filter full. It's a feature, not a problem.

[Moody46CC]

I have the turbo (75 hp) model and change/fill less oil that the manual says. Engine seems close to level, but I don't worry as long as the reading on the dipstick is at the top mark. After a change, I'll add 4.5 quarts, then run the engine and gradually bring the level up to the top of the dipstick mark. Usually over 5 quarts.

I've always figured there is some old oil that does not get sucked up owing to the way that little tube from the oil changing vacuum apparatus ends up in the pan. Not much control there.

[Dockhead]

My experience is the same.

It is alarming to think that the dipstick may be mismarked. Is there any way to check this?

One peculiarity of Yanmars is that you should NOT let the engine sit for a while after shutting down, to let the oil drain down, before checking the oil level. Yanmar want you to check it immediately, before oil has drained down. If you think about it, this is actually logical - will be better related to the level in the pan while the engine is running.

Sent from my D6633 using Cruisers Sailing Forum mobile app

[Russ]

FYI
On my Yanmar 110. The dip stick handle must point to front of engine to get accurate reading according to my Yanmar dealer. Also if you do not drain from bottom of block there is no way you are getting ALL the oil out. Russ

[bytownboy]

Thanks for all the help. Really appreciated. I will head down to the boat and suck out about one half litre.

I often wondered about the orientation of the dipstick. Due to the curvature of the dipstick tube I get a different reading on one side of the dipstick verses the other. I will pay attention to how it is orientated.

Thanks again

Doug

[delmarrey]

This is what came on my Yanny.
And btw after installing my Yanny I added the recommended amount of oil, then remarked the dipstick after a warm up and 10 minute rest.

.

[hpeer]

Struggling with this myself. All the above same issues.

However, while staring at the parts manual I noticed that there is a bolt into the pan on the port side. It mirrors the position of the dip stick entrance on the starboard side. It's as if you could mount a di stick on eithe side.

Anyway, the last time I changed oil I drained out of that plug into an oil pan. Easy peasy. Seems to work just fine.

Thanks for noting the recommended orientation of the dip stick. Just to be cleat by facing front you mean the top of the stick should be facing forward?

[doublewide]

I can't suck all the old oil out of mine, either, but not a big deal. Get as much out as you can and then fill to the mark, and bob's your uncle.

[Hudson Force]

I've developed the habit of removing the oil fill cap before checking my oil level. I found that, when I left the system closed, I would sometimes see unrealistic high and inconsistent levels on my dipstick. Pressure? Coincidence? Regardless, with the fill cap off I can always get the same reading when I check the oil twice in succession and not with the fill cap closed.

[delmarrey]

Originally Posted by Hudson Force

I've developed the habit of removing the oil fill cap before checking my oil level. I found that, when I left the system closed, I would sometimes see unrealistic high and inconsistent levels on my dipstick. Pressure? Coincidence? Regardless, with the fill cap off I can always get the same reading when I check the oil twice in succession and not with the fill cap closed.

There is a breather valve in the center of the rocker arm cover. It sounds like you need to clean it or replace the diaphragm.