Yanmar Oil leak on 4JH4
Printed From: myHanse.com
Category: Hints & Tips
Forum Name: 411
Forum Description: 411 Hints and Tips
URL: https://www.myhanse.com/forum_posts.asp?TID=774
Printed Date: 27 March 2026 at 03:29
Software Version: Web Wiz Forums 12.06 - https://www.webwizforums.com
Topic: Yanmar Oil leak on 4JH4
Posted By: Stephen
Subject: Yanmar Oil leak on 4JH4
Date Posted: 17 September 2006 at 08:55
|
Hi all On my Yanmar 4JH4 54 hp I have always suffered an engine oil leak from new. There is alway a pool of oil in the bilge. Constantly mopping up. Any ideas welcome. Engine still under warranty. regards Stephen ------------- Stephen Kerr |
Replies:
Posted By: colincooper
Date Posted: 17 September 2006 at 22:03
|
Evoke the warrentee. It should not leak like that. Should be clean. ------------- Colin (owner of Hilde - a 370) |
Posted By: Zeevlam
Date Posted: 08 May 2007 at 15:03
|
Hi,
Depends on what kind of oil it is: does it come from the saildrive or the engine itself. Common problem with the saildrive is oil leakage on the primary axe running into the saildrive. This oil is always clean and smells different. Regards, Willem |
Posted By: taduka
Date Posted: 08 May 2007 at 16:04
|
Stephen
if oil is leaking you should see levels dropping. monitor both your engine & sail drive levels very accurately and then you can establish where this leak is coming from. once this is identified action can be taken. if the engine is still under warranty you should ask yanmar to look at it
good luck
Shawn
|
Posted By: Zeevlam
Date Posted: 08 May 2007 at 16:26
|
Dear Shawn,
It does not really have to work that way! Leakage from your SD is not a matter of a dropping level. If it became that far, problems a huge by that time. Leakage from the engine cannot for 100% be concluded from a dropping level since your engine is also consuming oil. The simplest way is to smell the oil. One can also feel underneath the engine at the junction between the SD and the engine. Good luck, Willem |
Posted By: colincooper
Date Posted: 08 May 2007 at 20:38
|
The problem was reported 9 months ago. Hopefully it has been fixed already. A pool of oil in the bilge seems conclusive proof of a leak somewhere..... ------------- Colin (owner of Hilde - a 370) |
Posted By: Zeevlam
Date Posted: 08 May 2007 at 22:32
|
About the smell is just a hint ...
If the leak is found, perhaps interesting to know what it has been ... Stephen, any news? Greetings, Willem |
Posted By: tbbmarine-1
Date Posted: 28 September 2007 at 16:02
|
Can you be more specific as to the location of this common saildrive transmission leak- and suggest how best to repair. Is this a mating problem between the engine and the transmission- requiring gasket replacement? Or is this something else? I may have a very small leak but very small, and very hard to find. Can you tell me where to look? |
Posted By: Zeevlam
Date Posted: 29 September 2007 at 19:23
|
Hi, tbbmarine,
I do not really understand what you want to know since almost everything has been set out above. I also do not really understand the word "mating". But anyway, the engine and the saildrive are two separate elements but connected to eachother. From the flywheel an axis comes out of the flywheel house which runs into the SD. The flywheel is dry, meaning that there will be no oil leaking from that site, assuming that it is leaking just a bit. So, mostly the oil comes from the SD which is totalay filled with oil. To prevent oil comming out, the axis from the flywheel is covered with a seal. Now that one can leak which is a common problem at Yanmar. If that is the case, you can feel the oil comming down between the engine and the saildrive, just put your fingers in. If you feel the oil overthere, smell it and have a look at its color. Take out the oillevel plug from the SD and smell if its the same particular smell. That should point you in the right direction. If that is not really the case or only half the case, take a look at the color. Especially if the engine oil is gray or black and you can find that color also on your fingers, then it comes from the engine. If it is the saildrive, be happy to know that Hanse and Yanmar did a good design job: its quite easy to pull the engine from the SD and replace the sealing. If it is something else , you have to locate the leakage more in detail. In any event, I have been told that Yanmars are clean and dry during there lifetime. Good luck, hope it clearify's something, Greetings, Willem |
Posted By: tbbmarine-1
Date Posted: 01 October 2007 at 18:28
| hello zeeflam- thank you very much for the reply. My leak is a tiny amount- probably about 3 or 4 drops for each hour of running time- and it is certainly gear oil and not motor oil. The gear oil collects in the area you suggest. I suspect you are correct and I will eventually have to replace the seal. I had a look- and have to say it does not look easy- my sense is that the engine will have to come off it's mounts and getting a wrench on the nuts will not be so easy either. I know leaks usually get worse- but for a couple of drops it hardly seems worth it right now. WOuld you expect catastrophic failure if I put this off? Any detailed information would be most helpful. Thank you. |
Posted By: Zeevlam
Date Posted: 02 October 2007 at 08:20
|
Hi tbbmarine,
OK, nice to hear that the information has been helpfull. The sealing is something like a rubber ring which has a metal feather inside which tightens the rubber arround the axis. We call it a simmerring which is explained at http://www.eriks.nl/index.php?dynamischeafdichtin . Once you know this, two issues might be the cause of your leak. 1. The feather is broken, 2. the rubber is broken somewhere in the area where it meets the axis. In the first case, I do not really know when and how things will get worse. In the second case, I would not give it a try. It might very well be the case that the ring will be ripped in parts quite quick which causes a greater leak. In my case, I was under warranty, but discussed things with a dealer in Denmark, one in Holland and Yanmar Benelux. They all adviced me to have it replaced just to prevent that its the broken rubber (case 2) you're dealing with. In Denmark they gave me some spare oil and advised me to check frequently. I made another 70 hrs. before I was back home where they replaced it and things did not get worse in the meantime. So if you like to wait, check frequently and, in my personal opinion, it wont be the case that the SD will blow all the oil out at once, meaning, it can come to 10 drops or 30 drops an hour from one moment to the other, but then you will notice this during your frequent check. The problem then is, that you have to repair which might be during holidays or a moment that doesn't fit you. I think the bottom line is that you have to do it anyway. Now, regarding taking out the engine, right from the beginning, I had the same feeling as you have. I had the advantage that a Yanmar Dealer had to do the job under warranty so my concern was taken down to the proportions of chosing the right one. You know, one with mechanics who also know something about boats and wo would be able to take down parts of the interior without damaging. I found them, they exist. What they did, they took out the wooden panels around the engine. Wow, that realy put things in another daylight! Then they can realy and easily work on the engine. They made a kind of gliding construction, from wood, put it under the engine, dismounted everything, and glided the engine to the front (somewhere to the entrance of the toilet). After replacing the sealing, they mounted everything back again. No more than 2 days work! So far, all the best for you, greetings, Willem Bürmann |
Posted By: tbbmarine-1
Date Posted: 02 October 2007 at 13:06
| thanks again, very helpful. I will keep my eye on things, and if I can find a decent yanmar mechanic- I will likely get this done. Last time the boat was used, no drips at all...I wonder if my problem could have resulted from an overfill of the gear oil that happened when my local yanmar dealer changed the gear oil....I took the excess out once it was discovered. If anyone on East Coast of USA has any recommendation, I would sure like a refererence. |
Posted By: Nereide
Date Posted: 10 October 2007 at 14:12
|
I was slightly shocked to see that a 411 dismasted on the first race of the Hanse Cup this year (end of August). The boat is Brunella -
Does anyone have additional information as to why this incident occured ?
Brunella is registered on the German Hanse forum but we members can't access this forum with reregistering...
411 # 244
|