yanmar oil/breather questions

[VanIslandGuy]

My engine is a Yanmare 4jh2e. We recently changed the oil. We took the boat out for an hour motoring first to get the oil good and hot, then changed it straight away.

Service manual says 7 quart capacity. We had sucked 7 quarts out with a west marine extraction handpump vacuum tool. We put in 7 quarts of Shell t4 15W40. Once done, we checked the dip stick, ran the engine to make sure the engine oil was circulated, shut it down waited 10 minutes and checked the level again. All good so far.

I went back two days after the oil change, checked the level and to my surprise it was above the line.

Checking the dipstick on this boat has always been odd compared to other engines I've used. The oil forms a long v-shape along the stick, rather than a perpendicular line. The base centre of the V is where I'm guessing the "true" oil level is, rather than the high thin amount of oil up the sides of the dip stick.

So I bring back the extraction unit and draw roughly a litre or so out and once again the oil is on the line. I've never over filled oil before, but thankfully the engine hadn't been run more than 10 minutes at the dock with this amount.

Since the oil was overfilled I had concerns about the breather filter might be getting gunked up. To see if there was a lot of pressure I had my wife start the engine and warm it up. I removed the oil cap afterwards while running and observed fairly strong air pressure out from the cap opening. Here's the strange part. We put the boat in gear and put a good load on the boat eventually running around 1900-2000 rpm tied to the dock. The air pressure at the cap reduced substantially...

I've ordered up a new gasket for the breather cover, and once it arrives will pull the two bolts for the breather cover off and inspect. This way I can determine if I need to either clean or replace the oil mesh filter inside.

Questions

1) Am I the only one finding it a challenge to get a good clear reading off the yanmar dip stick? I can't think of any other motor, (car, truck, airplane, other diesel) that has been harder to get a good clear read on that I've operated in the past.

2) Does it make sense that the breather pressure would decrease when RPM's and load increase?

 

[Don S/V ILLusion]

See Yanmar service manual which indicates oil capacity is 7 liters, not quarts.

Oil pressure control valve, mounted on filter housing, should be set between 3.5 - 4.5kg/sq.cm.

The meniscus on the dip stick is normal but not typical of what you imply.

 

[Charles Erwin]

As to the crankcase you can take the cover off and clean the breather without a new gasket. Also make sure the tube from the cover to the intake is clear. Crankcase pressure will always decline when you remove the cap because cap removal creates a large ventlation path. Much more reliable to measure pressure with cap on. By the way is this motor turbocharged?

As to oil is the motor mounted on a slope. If so the stick mark will be wrong. Also is your 7 liters with or without filter or is the 7 full capacity including retention. (I don’t have your manual). The filter and oil chambers retain some of the 7 thus the stick mark is not 7 but actually a bit less so as to account for retention. Keep an eye on this. A fuel leak to the crankcase will make the oil level rise.

Charles

 

[VanIslandGuy]

I'm going to pull the crankcase breather cover off and take a look. If anything else I want to know if the level rose again after pulling some out meaning there is a leak, or if it was simply overfilled by a litre.

 

[Charles Erwin]

Yanmar wants a 3 minute wait after fill or shut down for reliable stick measurement. Also Yanmar operations manual says to fill to the top mark on the stick. So if 6 liters gets you to the top mark - stop

 

[Rick486]

My engine is a Yanmare 4jh2e. We recently changed the oil. We took the boat out for an hour motoring first to get the oil good and hot, then changed it straight away.

Service manual says 7 quart capacity. We had sucked 7 quarts out with a west marine extraction handpump vacuum tool. We put in 7 quarts of Shell t4 15W40. Once done, we checked the dip stick, ran the engine to make sure the engine oil was circulated, shut it down waited 10 minutes and checked the level again. All good so far.

I went back two days after the oil change, checked the level and to my surprise it was above the line.

Checking the dipstick on this boat has always been odd compared to other engines I've used. The oil forms a long v-shape along the stick, rather than a perpendicular line. The base centre of the V is where I'm guessing the "true" oil level is, rather than the high thin amount of oil up the sides of the dip stick.

So I bring back the extraction unit and draw roughly a litre or so out and once again the oil is on the line. I've never over filled oil before, but thankfully the engine hadn't been run more than 10 minutes at the dock with this amount.

Since the oil was overfilled I had concerns about the breather filter might be getting gunked up. To see if there was a lot of pressure I had my wife start the engine and warm it up. I removed the oil cap afterwards while running and observed fairly strong air pressure out from the cap opening. Here's the strange part. We put the boat in gear and put a good load on the boat eventually running around 1900-2000 rpm tied to the dock. The air pressure at the cap reduced substantially...

I've ordered up a new gasket for the breather cover, and once it arrives will pull the two bolts for the breather cover off and inspect. This way I can determine if I need to either clean or replace the oil mesh filter inside.

Questions

1) Am I the only one finding it a challenge to get a good clear reading off the yanmar dip stick? I can't think of any other motor, (car, truck, airplane, other diesel) that has been harder to get a good clear read on that I've operated in the past.

2) Does it make sense that the breather pressure would decrease when RPM's and load increase?

I chuckled when I read your comment about dip stick readings. I have a 4JH4E and getting an accurate reading has been a challenge since day 1 for me. I have evolved into a procedure that goes like this:
1. Let engine cool down
2. Open fill cap and remove dipstick to relieve any internal pressure.
3. Wait 5 to 10 minutes to let the oil level settle out.
4. Gently insert the dipstick. You will notice that the dipstick has a tight gasket at the top which increases the pressure in the dipstick tube, lowering the oil level.
5. Take multiple readings and average out the result. I find I get the best readings by inserting the dipstick only to the gasket, and just extrapolate the result.
Fortunately my engine consumes almost zero Rotella 15 40 so I don't often need to actually execute this procedure

 

[Rick D]

+1 Rick's method for our JH2E. I only fill to the top and never have put more than five quarts (with a fresh filter).

 

[Benny17441]

I may only go over the line when I try fill it to the line. I always fill it short of the maximum line, between 1/2 and 3/4 of the gap between the minimum level and maximum level. I give myself a wide margin of error so I don't have to fuss about the dipstick reading. Been doing it for years in boats and automobiles. That is the reason for having two lines so you can stay away from the limits.

 

[VanIslandGuy]

I chuckled when I read your comment about dip stick readings. I have a 4JH4E and getting an accurate reading has been a challenge since day 1 for me. I have evolved into a procedure that goes like this:
1. Let engine cool down
2. Open fill cap and remove dipstick to relieve any internal pressure.
3. Wait 5 to 10 minutes to let the oil level settle out.
4. Gently insert the dipstick. You will notice that the dipstick has a tight gasket at the top which increases the pressure in the dipstick tube, lowering the oil level.
5. Take multiple readings and average out the result. I find I get the best readings by inserting the dipstick only to the gasket, and just extrapolate the result.
Fortunately my engine consumes almost zero Rotella 15 40 so I don't often need to actually execute this procedure

I'm glad I'm not the only one! Thanks for all the replies.

I've just bought a breather filter, and gasket. The engine is 20 years old but under 500 hours. It's probably the first time it's been replaced so all good. I'll see if replacing the filter is necessary when I open the cover, and if not, they are cheap parts for spares.

 

[VanIslandGuy]

View attachment 157344 See Yanmar service manual which indicates oil capacity is 7 liters, not quarts..

True, quarts and litres as words often get used interchangeably for Canucks like myself as they are only 54 ml apart in volume. However, 7 quarts is 6.6 litres so less than the pan capacity. Also I replaced what I had put in (I always measure what I take out), and had the dip read on the line before the oil change. After the change it was on the line as best as I could read. Hence the confusion and why I posted originally.

 

[VanIslandGuy]

Just to follow up....

Pulled the breather off today. Filter and plate were clean. Pulled the tube off and could blow easily towards the silencer. Zero blockage. Phew, all is well.

I've run the engine a few hours now. The oil level hasn't changed so thankfully zero leaks from the fuel pump which was a concern I had. I found this thread http://www.cruisersforum.com/forums/f54/checking-the-oil-level-204522.html over at the cruisers forum with another H410 owner having the exact same dipstick reading issues.

For me I found the best way to check the oil on this 4jh2e is:

1) Remove the stick and wipe dry.

2) Insert stick slowly, especially during the last centimetre of insertion where the dipsticks top seal goes into the tube. I found this method referenced in the service manual, not the operations manual.

3) Remove the stick slowly when breaking the seal for the first few centimetres, then pull it out normally and read the stick.

Doing this gives me a much clearer reading on the dip stick and stops it from forming a funny V-shape with oil pushing higher along the sides of the stick than in the centre.

 

[SoSound]

Only on a sailboat could reading the dipstick be a complicated procedure... my biggest gasp came the time that I removed the dipstick on our brand new (probably less than 20 hours) Y3M30 and saw NOTHING! Checked it a second time and everything was fine.

 

[tfox2069]

Only on a sailboat could reading the dipstick be a complicated procedure... my biggest gasp came the time that I removed the dipstick on our brand new (probably less than 20 hours) Y3M30 and saw NOTHING! Checked it a second time and everything was fine.

I have the exact same experience with my 2009 3YM30, and I cannot for the life of me figure out why. I check the oil every time before starting the boat, and every time the initial pull shows NO oil on the dipstick. I re-insert, pull it out, and the oil shows at the proper level. That makes zero sense to me. If its sitting in oil in the first place, why doesn't it register at least SOMETHING on the first pull?

Would love for someone to explain this.

 

[tfox2069]

I have the exact same experience with my 2009 3YM30, and I cannot for the life of me figure out why. I check the oil every time before starting the boat, and every time the initial pull shows NO oil on the dipstick. I re-insert, pull it out, and the oil shows at the proper level. That makes zero sense to me. If its sitting in oil in the first place, why doesn't it register at least SOMETHING on the first pull?

Would love for someone to explain this.

So, I wrote to Yanmar to ask this question. The good news is that I got back a reply. The head scratcher is, it doesn't make a lot of sense. I mean, there's no way the dipstick gets 2-3" shorter during engine cooldown, right?? Maybe some of you can add enough of an explanation that the light bulb will come on. Here's the Yanmar answer, with my question below:


RE: FW: Question regarding checking the engine oil level on a 3YM30 [ ref:_00DD0pBbQ._5002o2BTkSK:ref ]

• Marine Service <marine.service-yeu@yanmar.com>
  To:tomfox_1@yahoo.com
  
  ‎Sep‎ ‎9 at ‎4‎:‎45‎ ‎AM
  
  Dear Sir,
  
  This is because of the engine cooling down after running, the dipstick is flexible aluminium which will take another shape because of the engine cooling down, when you pull out and pull in again it will get back in the original shape.
  
  Therefor just pulling out the dipstick is never a proper indication, you can also have oil residue on it, best way to do it is pull out, clean the dipstick and put in again to measure.
  when you do this you will have a correct and accurate measurement.
  
  With kind regards,
  
  Niels VIsser
  
  -------------------------------------------------------------------------------------------------------------
  From: Tom Fox <tomfox_1@yahoo.com>
  Sent: Friday, 6 September 2019 15:45
  To: ZZM info-ymi <info-ymi@yanmar.com>
  Subject: Question regarding checking the engine oil level on a 3YM30
  
  I have a 2009 Hunter 36 sailboat with a Yanmar 3YM30. I check the engine oil level every time before starting the motor, and every time the initial pull shows NO oil on the dipstick. I wipe the end of the dipstick, then re-insert, pull it out, and the oil shows at the proper level.
  
  I'm just curious why this happens. If its sitting in oil in the first place, why doesn't it register at least SOMETHING on the first pull? Other sailors with that engine on a website I frequent are wondering the same thing.
  
  Thanks for your help - love that little motor!
  - Tom
  

 

[DayDreamer41]

I have the exact same experience with my 2009 3YM30, and I cannot for the life of me figure out why. I check the oil every time before starting the boat, and every time the initial pull shows NO oil on the dipstick. I re-insert, pull it out, and the oil shows at the proper level. That makes zero sense to me. If its sitting in oil in the first place, why doesn't it register at least SOMETHING on the first pull?

Would love for someone to explain this.

Here my explanation to this observation, when you run the engine the oil level in the pan drops down below the level of the bottom of the tube, the top of the tube is sealed, shut the engine down there is no place for the air that is now in the tube to vent to, oil run back floods the pan but can't enter the tube due air pressure in the tube. So you will get either a low reading or no reading at all, until such time as you pull the dip stick and oil then equalizes in the tube with the rest of the oil pan.

Mark

 

[tfox2069]

Here my explanation to this observation, when you run the engine the oil level in the pan drops down below the level of the bottom of the tube, the top of the tube is sealed, shut the engine down there is no place for the air that is now in the tube to vent to, oil run back floods the pan but can't enter the tube due air pressure in the tube. So you will get either a low reading or no reading at all, until such time as you pull the dip stick and oil then equalizes in the tube with the rest of the oil pan.

Mark

Mark, that makes a lot of sense, thank you - a lot more sense than the aluminum dipstick suddenly contracting 2-3" when the engine cools down, and then magically gaining 2-3" so its back in the oil again after I've wiped the dipstick off and re-measured. Sounds like something a maintenance guy would tell a brand new 2nd Lieutenant to see if he would buy it. I figured it was the oil level changing when I remove the dipstick the first time, but couldn't figure out why. I'm not the most mechanical of guys, so this helps.

Edit:
Ran across this post on a different site which lends credence to the vacuum idea being a candidate for the initial "no oil" reading. Funny that the Yanmar tech didn't mention vacuum as the likely reason, but instead offered up the shape changing aluminum dipstick red herring.

Richard:

On my cat I have two 3YM30s. When I pull out the dipstick one always shows completely empty whilst the other shows the correct level. The first time I pulled out the dipstick on the empty engine I almost died of shock! However, the second time it is pushed in it shows the correct level but it is a bit variable.

I believe that one dipstick is making an airtight seal around the top of the dipstick tube and after the engine has been running and the oil level has dropped below the bottom of the tube, an airlock forms and, when the engine is stopped, the oil cannot flow back up the tube until the airlock is released.

It might therefore be possible that if the airtight dipstick is pushed in quickly or at a certain angle, it might pressurise the air slightly in the tube, pushing down the oil level a little. This will be variable depending on how quickly / accurately the dipstick is inserted.

 

[DayDreamer41]

We have a 4JH4-E and it does the same thing, the initial reading when you first pull the DS is below the add line, but on reinsertion it reads normal level. You would think that Yanmar would add this to their manuals, something like, "Oil level will not read correctly until the DS is removed, wiped clean and then reinserted, and reread."

 

[Ron20324]

... You would think that Yanmar would add this to their manuals, something like, "Oil level will not read correctly until the DS is removed, wiped clean and then reinserted, and reread."

You would think people learned that when they got their driver's license

 

[DayDreamer41]

You would think people learned that when they got their driver's license

While it is good practice to pull, wipe and reinsert to gain an accurate reading on the dipstick, the dip stick on a car protrudes from the end of the tube into the oil reservoir, while the initial read in this case might not be accurate there is typically a reading close to the actual (given the DS protrudes past the DS tube) oil level, while on a marine engine the reservoir is much shallower and oil covers the end of the DS tube resulting a an air lock in the DS tube causing a completely inaccurate indication of actual oil level.