checking oil Yanmar

[Navicula]

I have a Yanmar 4jh2e and on the dip stick it has two line marks....... when the boat has been sitting over night....12 hours and I check the oil.....the dip stick reads inbetween the lines.......then if I recheck over and over again.....it reads above the second line..........whats going on

 

[Sailgunner]

I will add to the issue. When mine is sitting for a long time and I pull the dip stick there is not oil. When I put it back in and pull it the oil is between the marks. What gives with that?

 

[Stu Jackson]

If your dipsticks have seals on them, you need to pull the dipstick up just a bit, then count to ten, replace the dipstick fully, and then pull it out and read it. Those of us with Universal engines have learned to do this since we got our boats. Don't know if that's how yours work, just an idea.

 

[Patrik]

To check the oil-level take out the stick, dry it with a cloth. Put it back and then take it out for check. The level must be somewhere between the marks.

 

[Rick486]

If your dipsticks have seals on them, you need to pull the dipstick up just a bit, then count to ten, replace the dipstick fully, and then pull it out and read it. Those of us with Universal engines have learned to do this since we got our boats. Don't know if that's how yours work, just an idea.

That's how mine works. There is a tight seal at the top of the dipstick. It seems to help also if you remove one of the fill caps first to break the vacuum.

 

[Roger Long]

It seems to help also if you remove one of the fill caps first to break the vacuum.

I've found this to be true on my older Yanmar. I don't know if the new ones the OP talks about have the same dipstick arrangement. If they do, the reading is very sensitive to crankcase pressure.

The dipstick on my engine is a separate tube that goes to the bottom of the crankcase. Any pressure differential between inside the crankcase and outside will therefore push oil up and down the tube, sort of like a barometer. I had some real adventures with wrong oil levels until I figured this out.

If your engine has the same kind of dipstick, it may need a minute or two with the cap off and the dipstick pulled out for the oil to come to the same level as the crankcase if the oil is very cold.

Don't forget that the engine pumps lots of oil up around it's moving parts and it takes a while for this to drain down. Readings right after shutdown will always be a bit low.

If you crankcase breather line has any low spots in it, oil may collect and block it. This can prevent the pressure from equalizing unless you remove the filler cap.

 

[Tim R.]

The problem with the 4jh2e is that the oil gets partially wiped off the dipstick when you pull it out so checking the oil level accurately is very difficult. Your best bet to discover how yours reads is to remove all the oil from the engine, fill with specified capacity and then see where it falls on the dip stick. This is how they calibrate the dip stick at installation.

 

[Navicula]

That's what I like about you guys......you solved my problem......this morning I unscrewed the filler cap..... Had a coffee and the checked...and I am good......so there is some kind of vacuum ....... Thanks

 

[Buck420]

Thanks Rodger, Tim, etal...
I, too, have a venerable 4JH2 and have wondered about the oil dipstick
reading "issue" for years, also.

 

[Roger Long]

Engines with breather issues, which include most Yanmars, I think should have one of these installed in the breather line:

It's an air / oil separator available from JEGS and other automotive supply places. They come with a filter element which is unnecessary and causes problems if it gets oil soaked. However, the element is easy to remove and discard. The unit then becomes a simple liquid trap that collects any oil that gets into the breather line.

This is as most as mine collects between oil changes. I check it during my engine room checks when motoring in a seaway. It not only keeps oil out of the engine intake (or engine room depending where your breather ends) but lets you monitor what is going through the breather.

If I ever have another head gasket failure, I may get early warning by changes in what I see in the bowl. I did with the last one but didn't know what I was seeing at the time.

 

[judybuddy]

Also, I saw some where, where the correct way to have the dipstick in the tube is with the finger pull, facing toward the bow.