Life Expectancy of a Yanmar 3GM30

[clausont]

This probably has been asked before but I have not found the information.

GI realize that given all of the variables such as maintenance actually performed, how the engine has been used, overheat problems, etc - there may not be any real answer. I was wondering how many hours can one expect the Yanmar 3GM30 to last under "normal" use in a sailboat (What really is normal use? )
Is 6,500 actual hours likely to be "over the hill"? What about the transmission? I think regarding the transmission one may have to ask if the engine hours are used mainly to propel the boat ir to charge the batteries. Or what percentage of each.

[Ram]

not sure, but i would think at least 6500 hours could be a lot more or less depending on how it was treated

[Chief Engineer]

Get an oil analysis done.....I think Gordon the Great has a link for a sample-it-yourself deal.

[Solitude]

I guess if I was looking at buying a boat with 65000hrs on the diesel I would do some serious thinking.

On the other hand I found this...

The Life Expectancy of the Marine Engine - BoatSafe.com

[clausont]

Great link and information, Solitude! Thanks - just what I was looking for.

[Jentine]

It is not unusual for over the road truck diesel engines to run for 500,000 miles before requiring any major engine work. They endure a far more rigorous life than that of a marine diesel that is run at a constant RPM for most of its life. I would consider that the standard Yanmar, with proper maintenance, would last for more than 10,000 hours. The engine will probably rust to death before it wears out.

[r.furborough]

It is my belief that road diesels have a much easier life than recreational marine diesels. They run in clean air, not moist salt laden air, have gears to help loading and get regular attention and run for longer periods for each start-up. Marine diesels are subject to a load that is equivalent to running up a long hill without the ability to alter gearing, run in a corrosive and hostile environment and particularly in a sailboat, get used for shorter periods of time with less maintenance due to inaccessibility. I do agree that 8 to 10,000 hours is feasable, but only with commercially operated engines that are overseen by professional engineers.

[Navicula]

I have been looking at sailboats and there is a price difference (reduction) when an engine hits the 5000 hour mark, 5000 hours seems high in the used boat market right now. this is my observation
I guess it means you may be looking at some engine repair soon

I have been into big block power boats for some time and the difference between a marine engine and a truck motor is that a boat motor need and uses alot of TORQUE, thats how it produces it moves, a boat is always under load, so they dont get the millage,hours as do trucks.

[Chief Engineer]

I have seen water taxis...with yanmars with more than 5,000 hrs.

Only saw one catastrophic failure.....Get a guy that KNOWS how to do an engine survey. Compression/leakdown test/oil analysis...

A real good sign is if the custome was "anal" about keeping receipts.

[MC01]

I recently took a basic marine diesel engine class. The instructor indicated that the marine Yanmars (and most other "light" marine diesels) are in a different class than the diesel engines used on the road or for heavy equipment. The aluminum components are more sensitive to abuse. He termed small boat engines "throw away diesels" in that once their life is up (up to 10,000 hours, but normally less?), they should typically be replaced rather than investing in a full blown rebuild. I'd be interested in hearing others opinion on this as well.

[Rex Delay]

It is the little things that go un-noticed that kills them. I had a Buhk with 2000 hrs, maintained very well. The water pump">raw water pump seal failed, sea water in oil, engine shot. They should last a long time but minor components can kill them very quickly. I also had a Volvo that was abused for it's entie life but would not die. It is a crap shoot. If considering a boat with anything over 2000 hrs on it, cost in a new engine in the offer.

[Chief Engineer]

Yes....Marine Diesels are designed for that purpose...but you will find the Yanmar Blocks used in all kinds of construction equipment, gensets, tractor skid steer loaders air conditioning/reefer units.

I don't know what you mean about the aluminum being sensitive...unless you put NALCOOL in it. or any other water treatment with sodium metasilicate......in it

Originally Posted by MC01

I recently took a basic marine diesel engine class. The instructor indicated that the marine Yanmars (and most other "light" marine diesels) are in a different class than the diesel engines used on the road or for heavy equipment. The aluminum components are more sensitive to abuse. He termed small boat engines "throw away diesels" in that once their life is up (up to 10,000 hours, but normally less?), they should typically be replaced rather than investing in a full blown rebuild. I'd be interested in hearing others opinion on this as well.

I have resurrected a lot of engines over the years....most mechanics/yards don't want, or ar ill-equipped to repair.....they want a simple swap out.....it is all aboot money.....

PS How much did you pay for the class?

I teach one-on-one.......

[Bash]

Originally Posted by Rex Delay

If considering a boat with anything over 2000 hrs on it, cost in a new engine in the offer.

please tell me this is hyperbole.

[Ram]

Originally Posted by Bash

please tell me this is hyperbole.

yes it is, its not hard to tell if the engine is in good shape if you know what your doing

[clausont]

I started messing with engines (gas) when I was about ten years old and bought my first car out of a wrecking yard when I was about twelve. At 17 I started running heavy equipment (backhoes, dozers, excavators, etc). That was thirty years ago. I still run equipment on occasion but that is not my main work anymore (would you believe computers and networking is?). So I have a pretty good background with diesel engines and have no problem rebuilding one if need be. I certainly know when one is in trouble But still, I am no expert on them. When it comes to the life expectancy in hours of the Yanmar, I am at a loss, but learning quickly.
I remember the first Yanmar that I messed with when I first started running equipment. It was a small garden tractor sized backhoe. I thought it was a complete piece of junk at the time with absolutely no power. I am glad to have seen the Yanmar prove me wrong from that time. They are an excellent engine!
I sure appreciate all of the information here - I am getting a great education!
BTW: we were always delighted when we were able to run a piece of equipment with only 2,000 hours on it - it was practically brand new!