How Many Hrs./Yrs. Can A Well Maintained Diesel Last?

iluvteak · Apr 17, 2010

yanmar estimate

I've always heard 10,000 hours on a Yanmar, but I'm no expert. I'm a big fan of Biocide, its always kept my Yanmar 50 hp starting on the first pull.

Stu Jackson · Apr 17, 2010

5,000 hours at 100 hours per year = you do the math. That's a very low estimate. One of my friend's who took meticulous care of his engine had to replace, but could have rebuilt. His choice.

Synthetic oil has been rumored to not be so good for seals. I have seen a tad more weeping on my oil pan seal since I went to synthetic, so now switched back. Sun advantages - less build up of stuff, lasts longer, can change only the filter between changes. More expensive, probably not warranted.

If your boat has a diesel engine, it's a big enough boat for Nigel Calder's Boatowners Manual for Mechanical and Electrical Systems. It covers diesels and everything else you need to know. If you buy this book, you won't need much else.

Ross · Apr 17, 2010

I know a farmer with a 1938 international diesel tractor and I have seen several wheel tractors with more than 10,000 hours.

Texas Lake Sailor · Apr 17, 2010

I served on submarines, one boat was over 30 years old. The diesels were strong, had been maintained, oil & filters changed and could have been pulled out put into something else. If you follow the op manual, do the preventive maint. there is very little reason why the engine shouldn't out last the hull. It is all about warm up, cooldown, maint. and running them correctly.

Paul Cossman · Apr 17, 2010

Diesel longevity

I have 5,000 hours on my 20 year old Yanmar 4JH2-TE. I maintain it diligently, (which mostly just means changing the oil every 100 hours, triple filtering all fuel, and doing all periodic maintenance/replacements as per the service manual such as raw water impeller replacements, checking fuel injector spray patterns, acid-dipping the heat exchanger, etc.). I just took my injectors in to have the spray pattern checked, and they were all perfect--still the original injector nozzles. I asked the head of service at Bosun's Locker, the Yanmar authorized dealer in Costa Mesa, CA, your question. He told me that he had just serviced a Yanmar 4JH2-TE that had 10,000 hours on it, and it ran perfectly. He saw no reason why it wouldn't run another 10,000 hours if maintained just as well.

garylinger · Apr 17, 2010

Re: Diesel longevity

From my recent experience, the worst thing that could happen is for the water jacket to clog with rust and other gunk.

Bill Roosa · Apr 17, 2010

Enging life

Truckers to to 400,000 miles before rebuild. At an average of 50 MPH that would be 400k/50=8000 hours of run time minimum as they probably don't average that high a speed

druid · Apr 17, 2010

I think the actual engine would probalby last forever. it's the little things that go wrong: water pumps, alternator, starter, heat exchanger, and so on. As long as you keep replacing those things and do your maintenance (oil, filters and zincs), they're outlast you.

druid

Bob16841 · Apr 18, 2010

sigbear said:
Can you recommend a good sailboat maintnance book for "dummies".

Thanks,

Sigbear

I have a manual entitled "Yanmar Diesel Inboard Shop Manual." It is by Clymer and covers one, two and three cylinder engines. Has 235 pages with diagrams and pictures...got it from Amazon. Don't recall the price, but it was reasonable.

Nereussailor · Apr 18, 2010

My Yanmar is original in my 83 H30. I have put on about 500 hours a year since I've owned it. If the previous owners did the same, that's about 13,500 hours. It still starts and runs great, doesn't blow any smoke, and has a lot of life left in it. Knock wood. I change the oil and filters twice a year, and check it every time I go out. I've never added any oil between changes. I use what oil Yanmar recommends in the manual.

Dave

Charlie13958 · Apr 18, 2010

So you motor 500 hours/year @ 5 knts, or 2500 miles/year. How many miles do you sail each year?

Nereussailor · Apr 18, 2010

About 1500-2000 miles a year. We sail between 25 and 50 miles every time we go out which is at least once a week. We sailed 25 miles yesterday, and motored the other 25. There's no tacking in the ICW.

Dave

Charlie13958 · Apr 18, 2010

Nereussailor, you are very lucky to be able to get that much time on the water.

CarlN · Apr 18, 2010

Have you gone to one of Mack Boring's boat owners training seminars for Yanmars? These are really excellent and are held in NJ, MA, and IL. Mack Boring brought the first Yanmar's to the US in the '60s. They obviously know these engines.

http://www.mackboring.com/training/Boat_Owner_Training.aspx

Here's some stuff I learned at the class:

Diesel fuel formulation has changed a lot in the last few years for environmental reasons. Mack Boring now recommends additives including Cetane booster and additional lubrication additives. You didn't used to need them. Probably still don't for low RPM traditional diesels.

Overheating kills more engines than wear (a lot of aluminum in a Yanmar). Change the impeller regularly and keep an eye on the whole cooling system (as Garry suggests). Make sure you can hear the overheat alarm and shut down immediately.

Make sure the engine gets enough air. There was a story told in class about inadequate engine ventilation, a movie star and naked starlets. Really

The more the engine runs at about 60%-75% RPM the better. If the engine has been idling (say for battery charging or a long run into the harbor) before shutdown give it three quick "gooses" of the throttle in neutral right up to max RPM to blow out any carbon or crap. Then give it a minute or two at idle and shut down.

Make sure that your prop is right. You should be able to just reach full rated RPM. Many boats are over propped and this really hurts engine life.

The time an engine is most without lubrication is at startup before oil pressure picks up. Even after the gauge shows pressure, the oil is still working it's way around all the parts of the engine. Keep it at slow idle for a good two minutes.

If the engine hasn't been run for several days more oil will have had a chance to drain down into the pan. If, like most Yanmars, your engine starts really fast the cylinders may be really dry. You can keep it from starting by holding the STOP button in for a three seconds while you crank to get some oil up into the cylinders. Then start normally.

Carl

henkmeuzelaar · Apr 19, 2010

My apologies for dragging up this older thread. However, a decade or so ago I did a fair amount of research on this topic (discussion should still be in the archives) and discovered that total number of engine revolutions seems to be the primary ageing factor for diesel engines. After a bit of calculation I figured that the maximum lifetime of a diesel engine appears to be 2-3 billion revolutions.
The amazing thing is that (as a first order approximation) this appears to be independent of engine size and average rpm!! In other words a small diesel engine being operated at an average of 3,000 rpm, as well as a giant supertanker engine running at a few hundred rpm both are good for about 2-3 billion revolutions.
Even more surprising may be that even the gasoline engine in your car is good for 2-3 billion revolutions! So, perhaps this rule can be extended to most internal combustion engines?

It may be a bit more complicated than that, however, since even the human heart (which, at best, can be regarded as an "internal bio-combustion engine") seems to max out at 2-3 billion cycles..... Go figure that one!

Maybe the powers that be just get tired after winding their toy engine springs more than a zillion times??

Have fun!

Flying Dutchman

larryw · Apr 19, 2010

expect 20k hrs on a well-maintained diesel.

Nereussailor · Apr 19, 2010

Thanks Charlie,
I am grateful for being able to sail all of the time. Living in Florida has been a Godsend when it comes to sailing. I try to get out a couple of times during the week, and we go out every Saturday or/and Sunday. It really beats living in Wisconsin. Short seasons, and all around cold weather, really make for little sailing. When I lived there, I sailed about three days a week, but only got to sail about 15 miles a day. with the short season, that only amounted to about 900 miles a year, and that included motoring. There's a lot to be said about Sailing in Florida. I think I'll stay here a while.

Dave

RichH · Apr 20, 2010

~10000 hours is typical for the well maintained Yanmar.

This includes:
• storage of the engine 'wet' (with antifreeze + rust inhibitors) and definitely never 'drained' .... to prevent the 'inside' of the cooling passages from 'rotting out'.
• have the proper pitch propeller ... so that the engine doesnt 'lug' and cruising rpm.
• Running the hell out of the engine This will keep up a good coating of black ferrous oxide on the engine 'internals', ferrous oxide is 'protective'.
• Making sure that the T-stat is keeping the engine ABOVE 180 deg. on the fresh water side of the ht. exchanger.
• religiously changing the TRANSMISSION oil
• keeping the engine in proper alignment (even when using a 'flex coupler').
• plus all the stuff that others mentioned above.

What kills a marine engine is: Rust on the 'inside', lugging the engine (hi load at low rpm), running engine the engine 'cold', ...... not running the engine long and hard enough so that the internal protective 'ferrous oxide' layer stays intact. If you dont keep a marine engine HOT, run often, the black ferrous oxide changes to red ferric oxide which is 'destructive'. Marine engines rarely 'wear out' they 'rot away' from the inside.

Blitz · Apr 20, 2010

Raw Water Cooled

Would everyone guess the same on the older Raw water cooled engines that many of us still have (no heat exchanger)?