Yanmar 4JH2E oil level

My little Yanmar reads two different levels on the dipstick, almost the whole difference between full and low on opposite sides of the dipstick. I wondered if this is a common occurrence for that engine, and how other owners handle filling "to the mark".

I have been going off the low side, but find myself often below the fill mark. It seems to me that it couldn't be any more full than the lowest side of the stick, but it bothers me and there is a lot of information (and opinions) on this site.

Looking for information more than opinions

My 4Jh4-hte reads the exact same way.

I've googled around but have found no consistent answers.

I try to keep one side near the low mark and one side on the high mark, figuring maybe the average is correct. ?

does one side look like factory marks the other not? Installers will mark the stick for the correct full as the engine is installed while the stick may come from the factory premarked for flat level installation.

Could it be one side for turbo engines and the other for NA?
A lot of those JH engines have turbos.

Call the NW distributor Cascade Engines in Seattle.

Probably one side gets wiped by something when you pull it out.

Oil is not going to climb up the other side, defying gravity. Assuming engine off.

Use the highest level seen.

There are only marks on one side of the stick. If I face the stick "handle" forward it reads one way, if I face it aft it reads the other. The oil levels are completely different on the two sides of the stick and there is absolutely no sign that it "wipes off" on one side of the stick.

One side or the other IS defying gravity. Reads the same way whether hot or cold, one side of the stick high and the other low.

Facts is, it is high on one side and low on the other! By the difference between full and add.

If stick has a bend and goes into engine at an angle, it will be different depending on how you position it. If stick has a bend, straighten it. Otherwise, just be consistent and use it as a reference on a known full sump after oil change.

Stick is vertical and has no bend in it. Oil level reads differently on the two sides of the stick ALL of the time, even after a fresh oil change. If it were something that simple I would not be confused with it reading differently on the two sides of the stick. I am being consistent, I use the low side and try to keep it just above the fill line.

I am looking for answers as to why, from people who have a Yanmar, not opinions from people who don't. No offense intended.

It was a head scratcher for me as well for our 4JH2-UTE, with two manufacturer marks on the dipstick and a third mark scratched in between them. The operaters manual wasn't much help either, stating lube oil capacity was between 2.5 litres (effect) and 7.0 (maximum).

Buried somewhere in the service or operators manual I found a notation stating the oil should be checked three minutes after shutting the engine down...this means if you check while running it'll look low, and if you check before starting it'll look high. Check your manuals at it might be different for your engine.

So...what I did is add one gallon plus one litre (which puts it about halfway between 2.5 and 7 litres) and now when I check three minutes after shutting down it's at the mark between the manufacturers marks. I've heard, but have no way of confirming, that the mark scratched into the dipstick was done by the mechanic who installed the new engine, because it accounts for the angle at which the engine was installed.

I have rebuilt a couple of JH series, and worked on many more, so I do know what I am talking about. There are different variations in how the stick is oriented, so yours may be different than what I am familiar with.

But you have a static pool of oil. A stick goes in, then comes out. And you are stating that the lower level on one side is correct? And gravity was defied and forced the oil to read incorrectly on the high side?

Are you going slow with the stick to avoid moving the oil around when dipping?

MurrayM said:

I've heard, but have no way of confirming, that the mark scratched into the dipstick was done by the mechanic who installed the new engine, because it accounts for the angle at which the engine was installed.

Click to expand...

My 4JH Turbo has a dip stick identical to your description and is not the original engine, hence, probably mounted at a custom angle. Low mark on one side, high mark on the other, and another scratched in between. When I change the oil, it comes out at the scratch, so I use the scratch.

Mine has no scratch. Where is the scratch located on y'all's stick?

Wait, that didn't sound right.

And what does effective capacity mean? That also confused me.

So Doug is the dip stick located in the center, considerably aft or fwd of center? The different propeller shaft angles (min to max angle) could be represented on the dip stick as applying to max angle and min angle (probably level).

Checking the oil level on JH series Yanmars has been a bit of a head-scratcher for quite a while. The dipstick tube attaches close to the bottom of the oil pan which is why you can use it to change oil. Any pressure differential between inside the crankcase and the outside will affect the oil level in the tube, sort of like a barometer. I had some real adventures with wrong oil levels until I figured this out.

If you crankcase breather line has any low spots in it or is clogged in any way, it can impede or prevent the crankcase pressure from equalizing. Next time you check the oil, try removing the oil filler cap and then pull the dipstick. Wait a few moments for the oil pressure to normalize and check it again.

Readings right after shutdown will always be a bit low because it takes a while for the oil to drain back into the pan. Yanmar recommends waiting up to 10 minutes, depending on the model, after stopping the engine before checking the oil level.

The latest version of my 4JH3E owner's manual recommends pulling the dipstick, wiping it clean, re-inserting and waiting 45 seconds. It has a rubber sealing plug at the top that when inserted into the tube, pushes some oil back down the tube. The waiting time, I presume, allows the oil to return to its normal resting level in the tube so you can get an accurate reading.

Hope some of this helps.

That's great info. Thanks!

The dipstick on my engine is just about centre on the engine, and only has marks on one side of the stick. The oil level on the stick is "clean" on both sides with no sign of dragging up the tube or contacting any other surface when withdrawing the stick from the tube. The tube IS very low on the engine, and as far as I can tell there is no external drain plug for the pan or oiling system.

I use the dipstick tube to suction the oil out for changing oil and filter. I will try removing the oil fill cap (there are two, one on top and one just above the oil pan) next time I am checking the oil. I always check it after shutting down, probably a couple or three minutes after shut down. There is no sealing plug in the top of my tube, but then again it is naturally aspirated and not turbo'ed.

The range of fill is also confusing, otherwise I would just fill it to "capacity" and note where the oil was on the stick. I understand that engine likes to run on the low side of capacity according to other Yanmar owners I have talked to. Their manual pretty much sucks They do note that overfilling the system can damage seals and such, something to be avoided.

Thanks all!

AKDoug,

I found my copy of the JH2 owner's manual. As you mentioned, it does say to wait 3 minutes after shutdown to check the engine oil.

What is strange is that it mentions the top mark being used on the dipstick at the '8 degree' mounting angle with 6.5 liters of oil. What marks do you use with the '0 degree' mounting angle and 8.0 liters of oil? Not very clear. Probably re-translated from the 'Engrish' version of the manual . . . .

I have attached a pic of that section.