oil levei

[tjandoverguy]

i have a yanmar 4jh4ae
when i pull the dip stick out ,make sure its all the way in,it shows oil on the bottom of stick,i put it back in full on one side low .5 gt on the other side??

[a64pilot]

Welcome to the marine world.
I believe the difference is because marine dip stick tubes stick down to the bottom of the oil, so that you can suck out the oil, where a cars does not, so when you shut down the stick cools off and sucks oil up or heats up and pushes it down, that is why you MUST remove the stick and wait a few seconds for the soil level to level out and then take a reading, a car you can simply pull the stick the first time and get an accurate reading.

I can’t explain the difference in the two sides but can tell you my 4JHE does that too. The higher level is the correct one on mine anyway.

[Sailing Drummer]

I’ve found that if I open the fill cap at the top of the engine I barely have to wait at all. When I do that then the dip stick reads properly. Otherwise it’s sometimes up to 30 seconds waiting by only removing the dip stick and not always the same reading on both sides. Not a big deal but I’m impatient! Just remember to put the cap back on - guess how I know!!!!!

[dfelsent]

For the most part my routine is to check the oil before starting each day. The engine has sat for hours at that point. Pretty stable readings over a few measurements. I’ve checked.
If I’m checking during a long run, it is definitely shut down. Pull and wipe dipstick. Wait. Insert and pull and measure. Maybe check again.
4jh4te

[FPNC]

Some of the very long and flexible dipsticks come into the block at a very acute angle to the top of the oil. They are sometimes not reading with the high degree of accuracy that you believe. It is not hard to imagine that the tip end of the stick is literally laying on top of the oil and giving this type of reading. Throw in that the engine can be installed at a steep shaft angle and possibly not level port to stbd. Dipsticks can read funny but they are pretty trustworthy. Twist it a bit and see what the reading looks like.

[Dsanduril]

Originally Posted by Sailing Drummer

I’ve found that if I open the fill cap at the top of the engine I barely have to wait at all. When I do that then the dip stick reads properly. Otherwise it’s sometimes up to 30 seconds waiting by only removing the dip stick and not always the same reading on both sides. Not a big deal but I’m impatient! Just remember to put the cap back on - guess how I know!!!!!

+1

Removing the fill cap also makes pumping out the oil a whole lot easier on our engine.

[noelex 77]

This is an unusual feature of Yanmar marine engines (at least on the models I have owned).

The handbook specifies the correct method for checking the engine oil. This involves shutting down the engine, waiting 10 mins, withdrawing the dipstick, cleaning it and then measuring the oil level. This works fine.

If measured in other ways the results can be significantly different, presumably because of a vacuum in the dip stick tube when the engine is shut down.

[CassidyNZ]

I’ve had this anomaly on three different Yanmars, have never been able to absolutely explain it. I’ve always believed that the lower one is the accurate level, based on the fact that a dipstick cannot be “clean” if it has been into oil.

I have put the “higher” level on one side down to the surface of the dipstick picking up oil off the inside of the tube on the way out.

[a64pilot]

If you guys need to remove the filler cap to change oil or check it, you need to clean your crankcase vent as it must be restricted, if it’s not restricted then it will keep the crankcase at atmospheric pressure, just like opening the cap will.
Removing the filler cap on an engine with a clear crankcase breather won’t do anything, as it’s already vented.

[a64pilot]

Originally Posted by noelex 77

This is an unusual feature of Yanmar marine engines (at least on the models I have owned).

The handbook specifies the correct method for checking the engine oil. This involves shutting down the engine, waiting 10 mins, withdrawing the dipstick, cleaning it and then measuring the oil level. This works fine.

If measured in other ways the results can be significantly different, presumably because of a vacuum in the dip stick tube when the engine is shut down.

It is from vacuum or pressure from the tube being below oil level, the small C-65 thru C-85 Continental aircraft engines do the same thing, because the dip stick is sealed and the tube goes below the oil level in the tank when it’s full. With the Continental aircraft engines, the dip stick is in the filler pipe, so it’s not due to the tube behind small as it’s probably an inch and a half big.

Being sealed after shutdown the tube will cool, form a vacuum and pull oil up in the tube making it look overfilled, so you have to remove the stick, let air in and the oil level return to normal, wipe off the stick and check again.

In a car that the tube does not go under the oil level you can check the oil first thing in the morning by pulling it out and looking, no need to clean it off and check again.