Yanmar 3JH2E Commissioning run and lost all oil in an hour

[Rafael8008]

My oil pressure alarm went off and I instantly shut the engine off.
After anchoring and subsequent rescue by Seatow, I started the ugly cleanup and diagnosis.
- I changed the oil and filter last fall before haul-out, exactly the same way that as I have done for 5 years
- The area around the oil filter appears high and dry. No sign of leaking at the filter
- There is break were a flexible tube meets rigid metal at what I believe is the oil pressure sender. I expected that monitoring to be all
signal wiring, but noticed it to be very oily. Has anyone ever heard of a pressure transducer failing and oil spewing out the housing?
- Finally I found a pretty big bolt in the engine bilge. It is 24mm long and 10mm in diameter. It looks similar to the bolts used to
hold the alternator's tensioning bar. (13 or 14mm socket)

I'm on the Hudson River, so thankfully do have access to mechanics and parts.
Any similar experience and fix would be most appreciated.

 

[kloudie1]

I've had two failures on automobiles where the oil pressure switch failed and oil came out of the electrical connection. ILooking at the pictures, I might suspect the pipe threads where the oil pressure sender is screwed in under the switch. I don't think that the engine came with an oil pressure sender, only a switch, so the sender was likely installed later.

 

[JoeWhite]

Yes, mine failed with oil everywhere. The pressure switch requires a special deep socket to be installed. I suspect the installer used a crescent wrench and crushed the cover causing it to fail later in time.
My engine M35B Universal, uses the same looking switch as yours.

 

[Rick486]

My oil pressure alarm went off and I instantly shut the engine off.
After anchoring and subsequent rescue by Seatow, I started the ugly cleanup and diagnosis.
- I changed the oil and filter last fall before haul-out, exactly the same way that as I have done for 5 years
- The area around the oil filter appears high and dry. No sign of leaking at the filter
- There is break were a flexible tube meets rigid metal at what I believe is the oil pressure sender. I expected that monitoring to be all
signal wiring, but noticed it to be very oily. Has anyone ever heard of a pressure transducer failing and oil spewing out the housing?
- Finally I found a pretty big bolt in the engine bilge. It is 24mm long and 10mm in diameter. It looks similar to the bolts used to
hold the alternator's tensioning bar. (13 or 14mm socket)

I'm on the Hudson River, so thankfully do have access to mechanics and parts.
Any similar experience and fix would be most appreciated.

I had exactly exactly that happen to me years back with a Westerbeke 4-107 in my Pearson 39. Just as we were picking up a mooring in Gloucester Harbor the alarm bell went off down below. I shut it down immediately and rushed down below to find the bilge was full of oil. Long story short I had a mechanic look it over and he found the oil pressure sensor had failed and a very fine mist of engine oil had leaked into the bilge. Fortunately the timing was just right........awful mess to clean up though.....always carried a spare sensor after that....

 

[capta]

The unit you show in the pics appears to be the crank case vent. If that is indeed where the oil is coming from, that would indicate bad rings in one or more cylinders. As oil and gasses pass by the rings, it increases the pressure in the crank case, spewing out oil.

 

[Ralph Johnstone]

My condolances on the failure as that must have been the mother of all messes in there.

This details the unfortunate mess you're looking at :

As others have said, it appears that the pressure transmitter diaphragm can fail and release oil. I'm living in the hope that the transmitter on my Yanmar doesn't go the same route :

You're going to hate this idea, but in order to find the culprit, first lightly wipe down the engine as best you can and then :

1. Refill your engine with oil to the correct level.

2. Carefully tape a polyethylene bag around the pressure transmitter and then another around the pressure switch. Wear eye protection if you have it. At least wear glasses. SAFETY FIRST.

3. Stand well back from the engine.

3. Leave your engine compartment cover off and have someone ATTEMPT to start the engine with the the kill lever pulled. DO NOT START THE ENGINE.

4. Shut down after 5 - 10 seconds of cranking and look for any oil under the plastic bags or from any place else on the engine. See @capta 's post #5

5. If no oil appears, have someone start the engine but have you in sight AT ALL TIMES. They must be prepared to kill the engine immediately on your signal.

6. Shut down the engine and inspect the bags.

I don't know your expertise around engines but BE CAREFUL. This is an excellent way to get killed if you don't know safety around engines. Basically, don't stick anything in the engine while its running.

See @capta 's post #5 and watch for this. Somehow I think this is a more likely cause than a failed sensor.

Let us know what you find.

 

[Rafael8008]

Great replies from the community. It is so appreciated, especially from those of us in the north, that are busy getting our own toys shipshape.

So, the update is as follows:
I cleaned up the bilge mess in bright sunlight and better attitude..
Again, could not for certain declare the source of the leak, but the evidence is all starboard, and aft of oil filter.

We had some knowledgeable folks on the dock, that were willing to help out solving this problem, (likely exercising their own curiosity as much as helping me. haha)

Basically we came up with the same list a Ralph Johnston's posted. There were NO LEAKS observed!

Then we escalated one step further. I drove the boat out of the slip and to our heavy floating concrete wave attenuator, that had no boats tied to it. A friend helped me tie up two long stern lines to the attenuator for the last test. This time we ran the boat in gear for 12-15 minutes, so under marine load to 1500, 2000, 3000 rpms. The oil pressure gauge held a rock solid, steady 55-56 lbs.

There were NO LEAKS observed! Despite our best efforts, we could not reproduce the engine oil problem.
Now, I will buy quarts of motor oil and marine absorption tampons.

Fair winds.

Shearwater
'98 Hunter 376
PS the admiral suggested that ordering spare transmitter and pressure switch from Yanmar would be most prudent.

 

[Rick486]

Great replies from the community. It is so appreciated, especially from those of us in the north, that are busy getting our own toys shipshape.

So, the update is as follows:
I cleaned up the bilge mess in bright sunlight and better attitude..
Again, could not for certain declare the source of the leak, but the evidence is all starboard, and aft of oil filter.

We had some knowledgeable folks on the dock, that were willing to help out solving this problem, (likely exercising their own curiosity as much as helping me. haha)

Basically we came up with the same list a Ralph Johnston's posted. There were NO LEAKS observed!

Then we escalated one step further. I drove the boat out of the slip and to our heavy floating concrete wave attenuator, that had no boats tied to it. A friend helped me tie up two long stern lines to the attenuator for the last test. This time we ran the boat in gear for 12-15 minutes, so under marine load to 1500, 2000, 3000 rpms. The oil pressure gauge held a rock solid, steady 55-56 lbs.

There were NO LEAKS observed! Despite our best efforts, we could not reproduce the engine oil problem.
Now, I will buy quarts of motor oil and marine absorption tampons.

Fair winds.

Shearwater
'98 Hunter 376
PS the admiral suggested that ordering spare transmitter and pressure switch from Yanmar would be most prudent.

Keep in mind that if this happened once, it can, and will, happen again unless you find the culprit and fix the problem. Were I in your shoes I would begin by replacing the parts referenced above, and any hoses or tubing which could have caused this. Then perhaps locate a shop which has the capability to test those components.
Again, were I in your shoes, having had this happen to me once, my worst nightmare would be a re occurrence of this failure while transiting the Cape Cod Canal, God forbid.

 

[Rick Webb]

Another potential source is the oil filter seal.

I once had an oil filter seal stick to the engine and did not notice. Installed a new filter on top of the old seal and dumped almost all the fresh oil between the old and new seal in like 30 seconds. It shot out as a high pressure stream and where the oil appeared was not where the leak originated.

Fortunately, it was a fast leak and I caught it right way a slower leak could have left me stranded.

 

[JoeWhite]

Oil can also come out of the dip stick if not inserted back in.

 

[Ralph Johnstone]

There were NO LEAKS observed!

Absolutely baffling. Just can't see how it corrected itself and went on with life as if nothing happened.

Keep in mind that if this happened once, it can, and will, happen again unless you find the culprit and fix the problem.

Completely true. If you're taking bets, I got two nickels, a dime, and a pocket lint ball that says it will happen again this season.

At the very least, I would replace the pressure transmitter as several people have experienced failures there. It's a "possibility" and right now , there ain't no others.

One last effort, let your engine sit for an hour or longer and take the oil depth on the dip stick as accurately as possible. Measure it exactly with a tape. Take the boat out and run it hard for an hour and return to shore. Let the engine sit for at least an hour or more to allow all the oil to drain back into the pan. Measure the oil again and see if there's a difference. I'm still worried about @capta 's theory in post #5.

Once you're under way again, I'd be inclined to shut down and check the engine condition every 1/2 hour or so. Do this only under calm conditions.

PS the admiral suggested that ordering spare transmitter and pressure switch from Yanmar would be most prudent.

Purchase these from an automotive shop unless you like spending money. They will be operating under automotive conditions.

 

[Dave]

At the aft end of the engine is the oil cooler loop. It is near the area identified ast the source of the leak. Check the hose clamps and hose

 

[dlochner]

If you don't have it already, here's a link to the 3jh2e service manual. It may be helpful in locating your leak.

YANMAR 3JH2 SERIES SERVICE MANUAL Pdf Download

View and Download Yanmar 3JH2 Series service manual online. Marine Diesel Engine. 3JH2 Series engine pdf manual download. Also for: 3jh2e, 3jh2-te, 3jh25a, 3jh30a.

www.manualslib.com

 

[Rafael8008]

Yanmar follow-up
I am pleased to report that there have NOT been any untoward oil leaks since launch day!
Unfortunately its been a lite, lite summer. less than 50 hours. Although we did push pretty hard against the current on the Hudson River last Monday, running at 3000 rpm for 7 hours.
The best theory so far, is that the oil filter was cold when it was changed last fall, and failed at the oil filter seat. Maybe a combination of skippers sloppiness, imperfect oil filter seal, and temperature contraction.
Thanks again for all your interest and support.
Fair winds.

 

[Rich Stidger]

Before I start changing suspect parts, I try my darnest to confirm the faulty part. If you can't confirm a bad part or fault, and just change parts, you will not know if you have fixed the problem.
I always like to find the fault, correct the fault, and observe that the fault is indeed gone. Peace of mind......

 

[kloudie1]

As a mechanic might say, "aim the parts cannon at it and hope ya hit the right one" Not a good diagnostic strategy..

 

[Rafael8008]

Follow-up from MAY 2023
The igmonius pressure sensor failed a second time. Exactly two sailing seasons later.
This proves what I have always suspected. I am a slow learner.
No damage. In friendly waters. Some humility.
The service shop around the corner found an off-brand on his stock shelf, with identical threads, that plugged the leak. He assured me that
although the readings on the pressure gauge would likely be unreliable, the temporary fix was safe.
The separate pressure alarm was not touched.
We motored 75 miles up the Hudson. There I ordered a Yanmar factory replacement.

Case is closed.
Have a safe, rejuvenating off-season in the northeast.


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
My oil pressure alarm went off and I instantly shut the engine off.
After anchoring and subsequent rescue by Seatow, I started the ugly cleanup and diagnosis.
- I changed the oil and filter last fall before haul-out, exactly the same way that as I have done for 5 years
- The area around the oil filter appears high and dry. No sign of leaking at the filter
- There is break were a flexible tube meets rigid metal at what I believe is the oil pressure sender. I expected that monitoring to be all
signal wiring, but noticed it to be very oily. Has anyone ever heard of a pressure transducer failing and oil spewing out the housing?

I'm on the Hudson River, so thankfully do have access to mechanics and parts.
Any similar experience and fix would be most appreciated.
[/QUOTE]

 

[dlochner]

I feel your pain. My oil pressure switch failed with nearly a gallon of oil in the bilge. At the time I was in Quebec and finding a mechanic was a challenge and ended up being really expensive.