[saltydog4]

Simple question that I'm sure has been asked before. What is the average life expectancy of an inboard diesel that has been well maintained? Measured in hours, not years.

 

[Dave_E]

I've got almost 3500 on my original 1979 Universal 5425... puffs a mere wisp of smoke at startup. But to answer your question, the answer I got the most when asking this question was: somewhere in the neighborhood of 5000 hours for any appreciable work, life of 10.

 

[jerryrlitton]

I have over 5900 on my Perkins 108.

 

[MarkSF]

Simple question that I'm sure has been asked before. What is the average life expectancy of an inboard diesel that has been well maintained? Measured in hours, not years.

This is one of those "how long is a piece of string" questions. To wear out could be anything from 5,000 to 10,000 hours, if used regularly and taken care of. I would venture to say that they rarely get replaced due to being generally worn out. What often kills them is some kind of accident where they get filled with water. Another problem is just obsolescence - lack of parts availability, especially for the marinised parts. As far as I know, the exhaust manifold is completely unavailable for the Universal 5424.

My 5424 has at least 3850 hours on it (I say at least, because the hour meter broke at 3,700, an unknown time ago.). I replaced it and have recorded another 150. No symptoms of wear.

 

[saltydog4]

I'm looking at a sailboat with a yanmar that has 3480 hours. Sounds like that is a lot.

 

[RichH]

8,000 to 10,000 hours on a well maintained Yanmar is not an unusual 'lifetime', especially the QM & GM versions.

 

[aeventyr60]

4800 hrs on a 20 year old Perkins 4108. I expect to get 10,000 ez.

 

[BarryL]

Hey,

My o'day 35 had a Universal M25 with about 5000 hours on it. I sold the boat last July. Last I heard the engine was still running great.

Barry

 

[travlin-easy]

My dad drove a diesel powered tractor trailer, beat the living hell out of the engine, and the first rebuild was at 350,000 miles and it was only a minor rebuild. I don't know what this translates to in hours, but it's a lot of hours. That was nearly 10 years of daily use and abuse.

Gary

 

[eherlihy]

The average car needs an oil change every 5000 miles. The average car averages 35 MPH - on average (city/highway/stop & go). This averages out to an oil change every 142.8 hours, but I'll call it 150 hours.

I'm willing to guess that the tractor trailer's average speed was ~50 MPH (less city, more highway), which means that he had the first rebuild at about 7000 hours.

 

[JimMcGee]

Most times when I hear of a diesel failure it's been overheated or ingested water.

Change your oil, belt, impeller, filters and keep the fuel clean and she should grumble along for many years. It really doesn't take much time to do.

The one thing I've never heard of is a motor dieing because it was too well maintained.

 

[RichH]

..............and the first rebuild was at 350,000 miles and it was only a minor rebuild.

350000mi ÷ ~50 mph (average) = 7000 hours. .... that's about the right time for a head/valve job, etc. 'rebuild' on an 'oil burner'.

 

[mike dryver]

Actually a truck diesel isn't broken in until about 40000 miles, or 1000 hrs, break in time. Truck engines if maintained well, will run over a million miles before needing major rebuilds. At least the old 1s I drove did. That would be 60s, 70s, 80s, and to mid 90s. Todays engines run better, and hotter, because of computers, but are built lighter for weight savings, ie better fuel economy. Also there is a lot of plastic, and aluminum on them. the engines hours should not dictate when it is time for a rebuild/repair. That is or should be dictated by the maintenance it has received, and or any issues that crop up during use, and how fast you can react to the problem, before you do damage!!!!!!

 

[MarkSF]

I'm looking at a sailboat with a yanmar that has 3480 hours. Sounds like that is a lot.

IMHO, an engine with those hours could have years and years of life left, or be ready for the scrap heap, depending on many factors. An engine survey will tell you which one is the case.

 

[rdw]

What is done in an engine survey? I am thinking if it is very invasive you might be better off to done some replacement work while it is apart.
Is there a good no invasive way to tell much?
Is an oil analysis worth anything?
I am thinking of doing the World ARC and my Yanmar (51 horse) has about 5,000 hours. It has been will cared for.
rdw

 

[Waltthesalt]

A big factor in reducing life is not running the diesel at power. Running for short periods and not letting it to get to temperature causes early failures.

 

[pikesbayone]

I did some research a while ago and came up with 10,000 hours. That was for a fresh water cooled small to medium sized normally aspirated diesel in an auxiliary sailboat application. I would expect less life for raw water cooled and less for turbocharged engines. For my friend who asked the question that worked out to about 100 years, as he only used his engine to get out of the slip and motor to the harbor entrance on most days.

 

[PaulinVictoria]

His will likely last a lot less then, diesels like to be warm and working hard for long periods of time.

 

[mbianka]

In 2007 my diesel died at 1900 hours despite regular maintenance, oil changes every 50 hours or yearly which ever came first etc.... Leak in head gasket sprayed water onto a cylinder and cracked it. Spent a lot of money trying to figure out why a formally good running diesel would not suddenly start. As others have said diesels do best when run long and hard. On sailboats they tend to rust out rather than wear out. Instead of a rebuild or replacement diesel I converted to electric propulsion and never looked back. It has been a much better fit with how I use my "sailboat" than with the diesel.

 

[Classic30]

FWIW, my boat has had three engines in 60 years - one every 20 years, more or less. That's for an auxiliary sailboat in and out of the dock with the occasional long run.

It's the marine (salt air) environment that gets to them in the end, not so much how often it's used although that plays a part. It seems rusting from the outside due to sitting at the dock or rusting from the inside due to breathing lots of salt air makes little difference in the end.