Reply
 
Thread Tools Display Modes
 
Old 07-13-2016, 06:41 AM   #1
Guru
 
Dougcole's Avatar
 
City: Carrabelle, FL
Country: USA
Vessel Name: Morgan
Vessel Model: '05 Mainship 40T
Join Date: Jan 2008
Posts: 680
Nuisance oil leak yanmar

Both of my motors, Yanmar 4HLA-STP, 240 Hp, 600 hours, have developed a small oil leak that is showing up in the same spot. I get maybe 1/4 to 1/2 ounce on the diaper just under the forward port corner of the oil pan after about 20 hours run time. No drip when the motors aren't running.

Not a huge deal, but I would like to eliminate it. Any idea of where to look for the cause?

Thanks.
__________________
Advertisement

Dougcole is offline   Reply With Quote
Old 07-13-2016, 08:06 AM   #2
Guru
 
Dougcole's Avatar
 
City: Carrabelle, FL
Country: USA
Vessel Name: Morgan
Vessel Model: '05 Mainship 40T
Join Date: Jan 2008
Posts: 680
I've been doing a little googling on this, and reading boatdiesel, it sounds as if I may be slightly overfilling my oil pan, especially since at fast cruise our boat runs at a fairly bow up angle.

I've always just filled to the top line on the stick, erring on the side of a little too much rather than a little too little (it's sometimes tough to get an exact reading). But they say better a quart low with these engines than a quart high.

Maybe I should run it a while just below the line, maybe 1/2 quart less, and see what happens?

I'm due for an oil change, and specs call for 2.6 gallons, I could put exactly that amount back in but I don't think that is all that accurate either as I don't think all of the old oil is completely extracted.
__________________

Dougcole is offline   Reply With Quote
Old 07-13-2016, 08:26 AM   #3
Guru
 
MurrayM's Avatar
 
City: Kitimat, North Coast BC
Country: Canada
Vessel Name: Badger
Vessel Model: 30' Sundowner Tug
Join Date: Jul 2012
Posts: 2,687
The manual for ours (4JH2-UTE) says to measure the dipstick 3 minutes after shutdown. There is also a mark scratched on the dipstick between the manufacturers high and low marks...presumably put there by the installer to account for the slope angle of the engine.

I'll look after work at my manuals. Pretty sure the operators manual is for the first time oil is added, and the service manual gives a different, lower amount.
__________________
"The most interesting path between two points is not a straight line" Murray Minchin
MurrayM is offline   Reply With Quote
Old 07-13-2016, 09:04 AM   #4
Guru
 
City: gulf coast
Country: pinellas
Join Date: Jun 2014
Posts: 1,949
It is common for the angle to require less oil to prevent whipping by the crank and subnerging some areas not intended to be submerged.


I always ran my cummins 2 qts low and oil use went way down.
bayview is offline   Reply With Quote
Old 07-13-2016, 09:29 AM   #5
Guru
 
MurrayM's Avatar
 
City: Kitimat, North Coast BC
Country: Canada
Vessel Name: Badger
Vessel Model: 30' Sundowner Tug
Join Date: Jul 2012
Posts: 2,687
The service manual had the amount (for our smaller engine) at 6.5 litres after reassembling the engine. The operation manual puts it somewhere between 2.5 litres and 7 litres.

Putting in a gallon plus a litre gives 4.8 litres, which is halfway between the minimum and max amounts and puts the oil level on the mark scratched into the dipstick...well...most of the time...because the dipstick shows a different level every time!

I can understand how the angle the engine is mounted at will create different results on dipsticks. For such an important thing, you would think they would make measuring the oil knuckle dragging simple and bang-on accurate every time. Having the dipstick curve into the oil at an angle seems like an afterthought.
__________________
"The most interesting path between two points is not a straight line" Murray Minchin
MurrayM is offline   Reply With Quote
Old 07-13-2016, 11:32 AM   #6
Guru
 
Pgitug's Avatar
 
City: Punta Gorda, fl
Country: Usa
Vessel Name: Escapade
Vessel Model: Nordic Tug 37 2002
Join Date: Jan 2015
Posts: 719
It is very common to use oil running only because the pan is on the high side. Yanmars are notorious for needing to drain for up to 10 minutes before you get an accurate read.
We found on river tugs that by running our Detroit Diesel 12V's a gallon below the low line we saved over 75% of the oil usage. That would be over 60 gallons of oil a month per engine.
Better to run on the low side and change oil a little more often for peace of mind.
Pgitug is offline   Reply With Quote
Old 07-13-2016, 09:40 PM   #7
Senior Member
 
City: Between Oregon and Alaska
Country: US
Vessel Name: Charlie Harper
Vessel Model: Wheeler Shipyard 83'
Join Date: Jun 2016
Posts: 268
Most diesel engines I have run over my life have used more oil if the oil level was at the top mark. Each one seemed to have it's own spot for lower consumption. They always use more oil if overfilled. My Detroit mains will use a pint an hour at the top mark. When they get to a quart low they stop using oil.
Diesels with several thousand hours and some blowby will often have increased crankcase pressure and high oil levels only make the pressure higher. Sometimes blowing out seals. Especially old style rope rear main seals.
__________________

Lepke is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





All times are GMT -5. The time now is 08:06 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012