Yanmar 4JH3E (56HP diesel) Lifespan

[viben]

The Yanmar 4JH3E seems to have a good reputation as one of the most reliable engines out there.

Any thoughts about this engine’s lifespan with regular usage and maintenance, ie. 5,000 hours, 10,000 hours?

What can one expect to experience towards the end of the engine’s life cycle, in terms of symptoms, breakdowns, repairs etc.?

Any other experiences worth sharing when it comes to this particular engine?

[a64pilot]

Usually the end of life for a Diesel is signified by hard to start (low compression) and excessive oil consumption and smoke and sometimes down on power ( low compression), low oil pressure when hot and idling is a sign of bottom end wear
Usually this occurs gradually, sometimes so gradually you don't notice, rarely is it a sudden onset type of thing. Excessive smoke is hard to not notice though and I have had farm Diesels than ran great, made great power with over 10,000 hours on them, but did blow blue smoke, especially if I let them idle for long.
Usually if the oil has been changed regularly the bottom end ( crankshaft, rods etc ) stays in relatively good shape.
Once in a blue moon an oil pump fails or other catastrophic failure occurs, but that is usually very rare, and truth be known can happen to any motor at any time.

As they get old age wise, number of years, they may begin to leak oil as the seals break down, but my Yanmar will hit 30 next year and doesn't even seep oil much less leak any, so that is not always true either.

Its almost like asking how long will I live? Some make it past 100, many don't make 50, but how an engine is treated will I think make it last a long time, or kill it early.
I have never, ever worn out a larger engine, I have run cars over 250,000 miles to where the car was falling apart, but the engine was still good, and I see many driving around with 50,000 miles on them and smoking.
But I have always wasted lots of money on the best oil and filters too, I probably pay twice as much for an oil change I do myself than I could have it done at a Jiffy Lube, but I use the best I can find, they don't.

I just sold last year the International Harvester 575 farm tractor that tried to kill me when I was a kid, looked like the devil, covered in rust, but started and ran great.

[ColdEH]

I chartered a 42 foot Beneteau a few years ago for two weeks in the BVI , it had a Yanmar 4JH3E in her and it ran great ! I went crawling around because I had to take a look at a motor that had over 7000 Hrs showing on the meter but it looked fine , no leaks no smoke nothing at all wrong with it . When I got back I asked the charter company if they had repowered her but they told me that was the original motor and that they have a very rigorous maintenance schedule on all there diesel engines in there fleet .

Regards

[Dockhead]

The Yanmar 4JH3 has a good reputation for longevity.

But asking how long it will live is like asking how long is a piece of string. It depends on a lot of things, including luck.

Failure prior to 5,000 hours is probably rare, and caused not be wear but some massive failure.

I would guess that most will make it past 10,000.

I wouldn't be surprised to see 20,000 hours before major overhaul, if the engine is taken care of and the hours are put on in a reasonable period of time (not 50 years).

My father's Perkins 4-108 had over 20,000 hours when he sold his boat last year, and still ran perfectly, started perfectly, didn't burn oil

But engines badly treated can fail at 2000 hours. Or if you're simply unlucky and something breaks.

[Vasco]

Just watch the oil cooler, it rusts out in about 2000 hours.

[reed1v]

Small diesel engines should last at least 50,000 hours if maintained. Big diesels can get into the 300,000+ hour range. All in how you treat the engine. Filtering the oil through clean filters a biggie. Multiple filters for the fuel important. Regular maintenance on clearances helps. Otherwise, operate the engine per the manufacturer's instructions. We are using a WW1 German built beast for power generation. Not sure of the hours on it. Its 100 years old and still going strong.
The only exception to this may be some of the new, light weight engines or converted gas engines that warp fairly quickly.

[jpstevens]

64 Pilot, what's your recommendation for oil and filters? (mine, a 3gm30f)

[jmschmidt]

Sorry to cut in on Viben’s post but does anyone have any experience, good or bad, with the John Deere 150HP turbo 4045TFM50?

[01kiwijohn]

Worked on a lot of these, as a professional serviceman, great engine. Really robust bottom end too.