Yanmar diesel bad sound then stalls

[HueyHuey]

I have a Yanmar 3jh2tce motor. Whilst underway I heard a scratchy strange sound coming from the motor immidiately before the motor stalled. Upon anchoring I found the starter cable had broken. I replaced the starter cable then found the relay had burnt out. I jumped the starter solenoid and the motor started but still had the sound, it ran underway for about 15 mins before stalling again. I changed both fuel filters which were overdue. Started the motor and the sound was still there, after about 10 mins the motor shook once (like when you remove a spark plug lead on a car) so I immidiately hit the stop solenoid to kill the motor.
My initial thoughts were fuel supply....
But now I suspect a faulty starter motor not disengaging and perhaps after heating up it puts a load on the motor and stalls???
This may explain the broken starter cable???
The starter is quite hard to access and would have to be done by feel only...

[HueyHuey]

I just started it again, it starts easily. By the sound is crackle scratchy sound that gets worse with engine revs, eventually stalling the motor.
I ran the motor for about 5 mins changing gears, increasing revs in neutral then cut the motor. I checked the temp of the starter motor by hand and it wasn't hot.
I restarted the motor and shorted the wires to the solenoid and it ground the starter gears.....
So my way of thinking is that the starter motor must NOT be stuck in engaged because it tried to re engage again.
So if not the starter what else would cause the noise and stalls the motor?
Could they be unrelated problems as my start battery got really hot and died as well???
If I was back at port I would get a mechanic out... but I don't think they will come out here...😫

[jamhass]

It would help if you could identify the source of the sound. A long screwdriver held against the ear can serve as a stethoscope. Hold the pointy end against suspect areas of the engine.

Absent more info, I would suspect a failed damper plate. Does the sound change in gear vs in neutral? Does the shaft turn normally in gear, or is there increased noise and vibration?

Other than the failed solenoid, what leads you to suspect the starter?

[HueyHuey]

I tried to locate the sound and it doesn't appear to be coming from the top of the engine, alternator, heat exchanger nor turbo. I could not get the steel rod down the side without bending it.
The sound is the same whether in neutral or gear but it does get worse with i increased revs.
Everything seems to appear to be running normally, no vibrations, etc.
It's just that noise that increases with revs until stall or I cut the engine...

[Lepke]

You should remove and examine the starter to rule out the starter staying engaged. The gear would probably be chewed up. Also the bearings could show wear or heat damage from running at engine speed.
How did the starter cable become broken? And the relay is the solenoid? If the solenoid stuck on and kept the starter engaged, both the cable and "relay" could have been damaged by too much current for too long.

Scratchy sound could be the damper plate or bad bearings somewhere. The alternator could have been damaged by the starter being on continuously.

[skipperpete]

I’ve heard the sound you describe and it was on a yanmar 4JH series that had lost all of its engine oil and the sound was a crankshaft bearing. The owner filled the sump again and tightened the oil filter which was the source of the leak and the noise went away but turned into a knock on a short but ill fated sea trial.
I hope your noise is only the starter motor staying engaged or the damper plate disintegrating but check the oil level and pressure to eliminate lower end seizure as the cause

[HueyHuey]

I don't know how either the starter relay switch nor the power cable to the starter became damaged. I do know that I have tried the starter battery, so it could have been due to a short.
The starter when shorted still starts the motor easily, but if shoted again while the motor is running it grinds like when granny tries to turn the ignition switch in her because she can't hear the engine....
So, if the starter re-engage, would that not.mean it must have disengaged after starting the motor?
When I put my hand on the starter after the motor has been running for 5 mins it's only warm...
Would the damper plate stall an engine?

[HueyHuey]

Ok, I just researched what a damper plate is.
How would a failed or failing damper plate stall a motor?
It doesn't stall when going into gear but later on?
Is there something inside it that could load up the engine to the point of stall??? It did smoke more than usual before stalling?

[jimbunyard]

If there're no clanking noises concurrent with shifting, or persistent rattlings, perhaps worse when out of gear, not sure if I'd suspect the damper plate itself at this point.

A part or bolt could have broken off inside the bellhousing and be caught somewhere between a moving and fixed part, an indication of that would be that the sound changes over time as the broken part is ground down...not a good thing.

Another long shot that I've never heard of but I suppose is possible is that the starter drive is solidly engaged. Most starter motors nowadays are of the permanent-magnet variety, so when turned by the flywheel instead of turning the flywheel, it would likely become a generator.

If the contacts in the starter solenoid were still engaged, this would send power back to the batteries, perhaps causing the problems with the starter cables and starter relay, and maybe even the stall if it is a good enough (haha) generator.

As I said it's a long shot.

Seems the best place to start is the simplest, if not the easiest. Remove the starter and check or have its function checked on the bench.

[skipperpete]

Originally Posted by HueyHuey

Ok, I just researched what a damper plate is.
How would a failed or failing damper plate stall a motor?
It doesn't stall when going into gear but later on?
Is there something inside it that could load up the engine to the point of stall??? It did smoke more than usual before stalling?

Some types of damper plate have a set of springs in them that occasionally shatter and fall to the bottom of the flywheel housing and get into the narrow gap between the flywheel and the housing. It might be possible to stall an engine with a broken spring lodged there but it would also be very hard to start.
If none of the suggestions in previous posts are the cause of the problem, you might want to eliminate my theory that you have a lower end seizure by spinning off the oil filter and cutting it open to inspect it for metal particles..... no shiny metal flecks.... no problem. And cheaper than getting in a mechanic.
I'm still hoping it's something simple and inexpensive though.

[HueyHuey]

Originally Posted by skipperpete

Some types of damper plate have a set of springs in them that occasionally shatter and fall to the bottom of the flywheel housing and get into the narrow gap between the flywheel and the housing. It might be possible to stall an engine with a broken spring lodged there but it would also be very hard to start.
If none of the suggestions in previous posts are the cause of the problem, you might want to eliminate my theory that you have a lower end seizure by spinning off the oil filter and cutting it open to inspect it for metal particles..... no shiny metal flecks.... no problem. And cheaper than getting in a mechanic.
I'm still hoping it's something simple and inexpensive though.

Wouldn't any type of seizure result in the motor not starting?

[skipperpete]

Originally Posted by HueyHuey

Wouldn't any type of seizure result in the motor not starting?

Well not exactly. The 4JH that had the loss of oil did initially lock up but later ( after it cooled down) it would rotate with the starter quite well but with a squeaking sort of noise not unlike alternator belt squeak but from low down. After figuring out what was the chain of events leading up to the shutdown ( owner still skeptical re diagnosis) the engine was refilled with oil and after about 10 seconds of rotation with the stop activated the noise went away and we started the engine which then ran quite normally...... until the seatrial when the knocking began and the decision to open up the engine was made.
My guess is that there is always a tiny bit of lube oil splashing around in the crankcase, just enough to un seize the bearing.

A seizure may not necessarily be caused by lack of lube oil but by a gradually loosened bearing cap which allows the bearing shell to rotate in the bearing cap and and seize briefly but still have a supply of lube oil available once the journal broke free at the next start.
Following this theory further, the power required by the starter to initially rotate the seized shaft could be great enough to burn the starter motor, solenoid or cables.
It's only a theory, but if you don't find a simple reason for the engine's behavior then it might offer a possible new line of thought.

[Big Joe Bob]

If the starter does not disengage, then after a few minutes it will start to burn and eventually go on in fir, believe me I know this from experience

[jimbunyard]

Have you checked to make sure the starter is securely bolted to the engine? If you have an oil pressure gauge, did you notice any variation from normal? If you have a low oil pressure warning light or alarm, did it activate? Is the oil level normal? What does it look like on the dipstick? Are there any loose fitments in the general vicinity? Does the engine overheat?

[HueyHuey]

Originally Posted by jimbunyard

Have you checked to make sure the starter is securely bolted to the engine? If you have an oil pressure gauge, did you notice any variation from normal? If you have a low oil pressure warning light or alarm, did it activate? Is the oil level normal? What does it look like on the dipstick? Are there any loose fitments in the general vicinity? Does the engine overheat?

Yes starter is secure. No pressure gauge, but motor did not overheat, oil level is ok as is quality...