Life expectancy of yanmar Diesel engine

[Capt Robbie]

If you maintain your equipment and do regular routine maintenance work like oil changes, lubricantion, and change out worn out parts, there is no reason why these engines should run forever. These deisel engines are built like tanks.

 

[dLj]

You have the top end and bottom end of the engine that wear differently. The bottom end typically out lasts the top end. I've rebuilt the top end of several diesels with the bottom end still in good shape. If you are changing your oil as needed and using the correct oil, then the bottom end should easily out last the top end. The top end of the engine is usually checked through compression testing. I did have one diesel where I pulled the head, then measured the gap in the rings. I did replace the rings in that engine and kept on running. To my knowledge that engine is still running today, about 20 years later.

I'd be very interested in knowing if anyone has ever done differential compression testing on diesel engines. I don't know if it's possible given the compression levels in diesels. In aviation engines, that is how they do compression testing and it is a superior method to the traditional direct compression testing typically done on diesels and automotive engines. Does anyone know if that is possible on a diesel engine?

You say you are very good at routine maintenance, so if you now run a compression check on the engine, compare to manufacturers specifications to be sure you are within spec now, then in a couple years (pick your time interval) run another compression check and see how they compare. You can then begin to get a running log of the compression results over time and that may give you a better feel moving forward as to how your engine is doing.

You have a fresh water cooled engine - so if you are using the correct coolant and changing that at regular intervals (usually once every few years - one way of knowing when to do that is checking the pH of the coolant) than you are not corroding from that side of the engine.

You may wish to pull the injectors and have the spray pattern checked. Most truck repair shops have the equipment to do that.

dj

 

[Doug4bass]

I would cook my breakfast on that engine.

 

[Capt Robbie]

Thanks all for the compliments,
Funny thing Doug4bass we actually did reheat left over spaghetti and meatballs for dinner one time on top of it. We were cruising to Block Island one year when our stove broke. When your out on the water and thing go wrong as a seasoned sailor you learn to adapt.

As far as my regular maintenance routine I have never done a compression test. Interesting? Don't no if I really want to start messing around with a 35 year old engine. Kind of feel like if it is not broke don't fix it. Afraid of opening up Pandora's box.

I think I will stick with my regular routine.
Winter: pump out oil, in the block and trans, replace filters oil/fuel.
Check belts and clean electrical connections dielectric grease.
Flush engine raw water sys with windshield washer fluid then nontoxic antifreeze. Change out coolant and impeller every other year. Cost me approximately $100 per season to do it myself which is the key. If you do the work yourself then you know it's done wright.

The key to a clean engine is spay it down with dawn warm sudsy fresh water in a spray bottle. Light scrub with soft bristle brush and light rinse off every few weeks.

I've been doing this for 35 years now, seems to be working so I am going to stick with it

 

[Valerio]

6,000 hrs at 4.5 knots= 39,000 nautical miles= a life at sea.
what kill engines is charging battery at idle and rust, with oil change a diesel engine on a truck will do at least 1.5 millions mile before a mayor tune up, injectors, water pump etc. and be ready for another million mile before teardown.
1.5 million miles at 65 mph is like 23,000 hr of operation.
Marine diesel will died for rust before they can died for use.

 

[Stu Jackson]

what kill engines is charging battery at idle

This is an oft-repeated urban myth.
Why?
Because at IDLE an alternator will not be running fast enough to produce any useful power. I define idle as 800 to 1000 engine rpm, which, of course, is measured via the alternator to the tach.
To be able to get any meaningful alternator output, I have found that the engine speed needs to be AT LEAST 1500 rpm. Often 1800 rpm works even better.
This produces a LOAD on the engine, albeit just the 2 to 3 hp needed to run the alternator with the engine in neutral. Neutral is not necessarily idle, right?
I have an M25 Universal, 21 hp, 3370 engine hours, 100A alternator with a Balmar MC-612 external regulator. I have a Link 2000 that allows me to track voltage, amps and bank ah.
I find that running the engine for an hour if I'm staying at anchor for more than one night provides enough bulk charge in that time to get enough amps back into my 390 ah house bank to tide me over for the second night. With a partially depleted bank from a day of running the DC system to get to my anchorage, I find that I can get a bulk-stage charge of 50A when first starting, which, of course, reduces slowly with battery acceptance. Once the amperage starts trailing off substantially, I just shut the engine down.
And solar would be a better solution!

I'm workin' on that next.

 

[MitchM]

during the mack boring yan mar HQ advance diesel course -- larry berlin told us mack has a yan with 100,000 hours on it still running fine . something to aim for ! by the way if you have a yan take the courses basic and advance diesel from mack boring . it has probably saved me thousands in boat engine mechanics fees. and that does't count all the free advice handed out to good friends whose engines won't start...

 

[shemandr]

+1 on Larry Berlin, whose course I took. For the record he didn't oppose running the engine at idle on the mooring to charge the batteries because it would shorten the life of the engine. He opposes it because it is ineffective in charging the batteries. I have to admit I don't remember if he instructed us to not run the motors at idle for long periods of time to extend the engine life. Several other sources have convinced me not to run diesels under their ideal power output for very long.

 

[kmacdonald]

6,000 hrs at 4.5 knots= 39,000 nautical miles= a life at sea.
what kill engines is charging battery at idle and rust, with oil change a diesel engine on a truck will do at least 1.5 millions mile before a mayor tune up, injectors, water pump etc. and be ready for another million mile before teardown.
1.5 million miles at 65 mph is like 23,000 hr of operation.
Marine diesel will died for rust before they can died for use.

They usually get pistons, rods, and rod bearings at about 600K to 700K miles. More than that and the risk of ruining the engine due to rod or piston failure is unacceptable.

 

[Dalliance]

Flush engine raw water sys with windshield washer fluid then nontoxic antifreeze.

Your are obviously taking excellent care of your engine, but windshield washer fluid? I have never heard of this and I’m curious about the logic for running wiper fluid through your raw water system before the antifreeze. Cleansing properties? Economy?

 

[dLj]

+1 on Larry Berlin, whose course I took. For the record he didn't oppose running the engine at idle on the mooring to charge the batteries because it would shorten the life of the engine. He opposes it because it is ineffective in charging the batteries. I have to admit I don't remember if he instructed us to not run the motors at idle for long periods of time to extend the engine life. Several other sources have convinced me not to run diesels under their ideal power output for very long.

Probably a great course, but it appears they no longer offer it...

dj

 

[Capt Robbie]

I have been running a gallon or so of -20 windshield washer fluid thru the sys for about twenty plus years now. Sometimes a will run a gallon thru a week or so before I actually winterize the engine an let is sit.
1) Helps to clean any build up, slim, carbon, or whatever is within the exhaust system.
2) Displaces any saltwater in the system with a liquid that will not freeze.
3) Now when the non-tox is added everything is clean and the anti corrosive agents can Côte the entire system better without any crud within the system.

I usually set up a bucket with a jack stand to reclame any fluid that comes out of the exhaust and dump it into the head long with
non- tox.
Doing this gives me piece of mind that everything is a clean as it can be and that a have good anti freeze protection throughout the system.

 

[Dalliance]

Capt Robbie,
Thanks for the explanation. Makes perfect sense.
I will consider adding this step to my winterization routine.

 

[Paul Cossman]

Just FYI, my 1991 Yanmar 4JH2-TE has 6,600 hours on it. I do regular maintenance, and it runs like new. I haven't done a compression test since about 4,000 hours, but since it's still got the power it has always had, that's on the list of "if it ain't broke, don't fix it."

 

[dakno]

No serious smoke, easy start, no real rust(this tells me everything about a sailboat diesel in salt water), clean fuel and oil is its life. You could always do a comp. check and that should answer all of your questions. Sounds like a lot of hrs to me. My 1981 1gm has a guessimated 360 hrs, ie.. 10 hrs per year. This has been our typical usage since new. Our 10 gallon fuel tank typically takes 2 gallons per season to fill. Its a real challenge to keep fresh fuel. You are estimating 100 hrs yearly, thats a lot of motoring.

 

[Capt Robbie]

My guesstimated hrs is based on 35 years of costal cruising to Newport RI from New Jersey with about 100 plus hours per year.
And I believe that my estimate is on the lower side of the spectrum, I think that the actual hrs are probably much higher.
Anyway the engine shows no signs of power lost, excessive smoke,
Or ware of any kind. She still purs like a kitten.
I am going to go with my instincts that if it is not broken don't fix it.

 

[dLj]

I'd guess by now you have your answer. Your original question of should you be saving up for a new engine probably is the same answer to the question should you be saving up for a new boat.

Some of us have intrepreted that question as what can you do to better understand the condition of your motor and have offered suggestions as to how to more easily determine that. Others have intrepreted that question by applying, perhaps holistic, points of view and responded accordingly. In the end I feel all have said essentially the same thing. Your motor is most likely in great shape. But none of us have a crystal ball to know... as the sayin' goes, Just keep on keepin' on...

You say you sail to Newport - I'll be there when the Volvo fleet comes in, if you are around perhaps we can have a pint, as the Irish say...

dj