Diesel engine life expectancy

[boaterdude1]

I am looking at a boat with a 160 hp Ford Lehman with 4000 hours on it. It is 26 yrs old. Is it a spring chicken or way overdue to die? It runs good. How many hours is typical before a rebuild?

[sww914]

I disassembled my Perkins with 4100 hours to reseal it. I measured the bearings, inspected the bores, etc., and decided to do nothing more than the reseal and replace the lift pump, fresh water pump, alternator, belts and hoses, rebuild the injection pump and injectors and any normal wear items that were much much easier to replace with the engine on an engine stand in a well lit shop rather than down in the bilge. It simply wasn't worn enough to bother with.
I have a friend with an Isuzu 4 cyl diesel that has 60,000 hours on it and it still doesn't use any oil. 60k is 9.8 years of 24/7. It's on a refrigerator so it's constant load and constant temperature, the best of conditions.
A commercial fisherman friend just replaced his Cummins engines that had 40k on them.

[Hudson Force]

Age and hours don't seem to be qualities alone that are very meaningful. Old engines with many hours, as cited above, can be in excellent condition; while a near new engine can be trashed in it's early hours with poor care. I've known people to destroy a new overheating engine by continuing to run it back to the dock when they could have saved 12,000 dollars by dropping the anchor and calling for a tow. They also could have opened the kingston valve before the run! Check and see if the former owner of the Ford Lehman kept maintenance records. Those 4,000 hours could be young hours if the oil was frequnetly changed and valves adjusted, etc. People that have these long lived engines keep a record.

[roverhi]

On boats, especially sailboats, think it's the disuse, not the use, that shortens engine life. Diesels are 10,000 hour or more motors but most don't get anywhere near that in a boat. Condensation from lack of use, unmaintained cooling systems, infrequent oil changes, etc. all shorten the life.

In your case, the number of hours is quite low but way more than I put on an engine on a yearly basis. If the engine starts easily from cold, doesn't smoke more than a normal diesel and doesn't overheat after a long run at full or lesser throttle, it's probably good for at least that many more hours. As CaptForce said, get the maintenance records on the engine. That may tell you more. An oil analysis is another way to pick up on any impending problems though a trend analysis from several samples over a period of time is probably better.

[hellosailor]

Oil analysis, about $25. Prepaid kit from Blackstone Labs via their web site, or similar available at many auto/marine stores.

If it was treated properly, 10,000 hours between overhauls is not unusual for a diesel. Should be good for 5000 in any case unless abused. But the oil analysis and a checkup from a mechanic are in order in any case.

[VirtualVagabond]

I've got a 120hp Lehman too and was concerned about it's condition because the previous owner had no idea what the hours were, but he had a complete rebuild in 2006. He just changed oil and filter every 200 hours, more or less.

I contacted American Diesel Corp which was set up by the guy who set up and ran Lehman for Ford in the UK for many years. According to them these engines outlast the boat if looked after and 25,000 hours is the absolute minimum you can expect.

If it starts easily, doesn't smoke too much, has clean oil and pressure around 28 psi and doesn't overheat, it's a sweet engine. Just service regularly and don't worry about the hours.

Vic

[boaterdude1]

Thanks for the input from all. Very helpful.