Life expectancy of yanmar Diesel engine

[Capt Robbie]

I am the original owner of 1983 h34 with a yanmar 3gmf freshwater cooled engine. I have done all regular routine maintenance suggested by the owners manual oil, trans, belts, impeller and so on. Replaced normal ware and tear items of the years. Winterized engine every year with no issues, engine startup every time on the first time. Knock wood! I have no engine hours meter so I can only approximate the hours to be 3500 - 4000 hrs.

Question is when do my fellow boaters replace or do a complete overhaul.
I ask this because I have a bobcat excavator with roughly the same size engine and I consider this engine to be used extremely hard compared to the boat.
The bobcat service center doesn’t recommend any major service or overall until 15,000-20,000 hrs as long as routine maintenance is done.

Should I be saving up for big bucks, am I way overdue, or put it out of my mind for now. I have gotten mixed views on this.

Some people say it’s a time bomb, others say that it’s just broken in.

Now I don’t want to sound like I am tooting my horn but when is say the engine looks and runs just like new it does. I am a firm believer in preventive maintenance.

 

[leo310]

If your not having problems keep going the way you are. I too have a Yanmar with over 2500 hours and would not even look at overhauling it unless I find a major fault. I seen some overhaul their motors and had nothing but problems after. So if its not broken what do you want to fix?

 

[Capt Robbie]

I agree
What do people think are a lot of engine hrs.

 

[jon hansen]

don't fix what ain't broke is what i go by. you can read the tea leaves so to speak. performance, sound, black soot build up on hull near exhaust. the next step if you want is to send in your used oil to a lab to be diagnosed just like the commercial vessels do. if you were to lose the engine you can always sail home.

just my 0.02 s

 

[AlastairLC]

That is one clean looking engine and compartment! If that’s any indication of how you treat it, you’ve got nothing to worry about.

 

[HMT2]

Life expectancy of yanmar Diesel engine

 

[shemandr]

Larry Borland (Sic) of Mack Boring told us in his course that the current (7 years ago) Yanmar diesels have a serviceable life of 20,000 hours. He went on to say that the reason it is that "short" is that Yanmar has to include emissions as part of the life cycle. Otherwise it would be much longer. So keep doing what you are doing.

 

[Calif. Ted]

I asked a guy who ran a fleet of shoreboats that used 3GM30F engines how long they last, he said "I don't know, we just rebuild or replace them every 10,000 hours."

 

[Capt Robbie]

So by the response so far a 35 year old with 3-4K hrs yanmar deisel engine can run for many years and hours without any major rebuild as long as the routine maintenance is done and keep anything clean and in working order.

 

[Gunni]

That is pretty low hours for an engine that old, you might not be running it enough! Run it up to operating temp, don’t lug it, change the coolant, don’t overheat it and keep the fluids clean.

 

[leo310]

The main thing that you want to check is you compression if low then you need a overhaul, check the manual for what your normal range for compression should be.

 

[Calif. Ted]

I hate to say it but your engine LOOKS better than mine with only 700hrs.

 

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[Roland5048]

CR, why is there a piece of tape over your air intake? Just curious.

 

[kmacdonald]

A lot of the small diesel generators that use the same Perkins, Kubota, or Isuzu base engines are rated at 30K hours and they last that long sometimes. Very often when they reach that they have accumulated those hours over a relatively short period of time, say 5 years. Those engines are also used in farm irrigation systems and seem to run forever. It's usually the heat exchangers, exhaust manifolds, water pumps, alternators, etc that break or wear out and not the base engine.

 

[Capt Robbie]

Roland
The tape on the intake is for winter layup
After the engine is winterized I soak two rags with w-d40 and stuff the rags into to air intake and exhaust port and tape them to prevent moisture from entering the piston and rusting.
Mac Boring seminar I attended in the late 80s recommend to do this as part of winter lay up. The W-d40. In theory prevents humidity moisture in the air from getting into the cylinder wall.
I have been doing it for 30 years don't know if it really does anything or not but figured that it can't hurt.

 

[Skipper]

A lot of the small diesel generators that use the same Perkins, Kubota, or Isuzu base engines are rated at 30K hours and they last that long sometimes. Very often when they reach that they have accumulated those hours over a relatively short period of time, say 5 years. Those engines are also used in farm irrigation systems and seem to run forever. It's usually the heat exchangers, exhaust manifolds, water pumps, alternators, etc that break or wear out and not the base engine.

Yep. Age can kill a motor just as dead as wear. Add to your above list: seeping gaskets, bad injectors, corroded bell housing/thermostat housing/other aluminum bits, carbon in the head, rusted through pan, etc. Maybe doesn't need a rebuild in the true sense, but a refurbish. $5k worth by a yard. If I've got 5k for refurbishing a 35 year old motor, boy-howdy I've got $8k for a brand new motor instead.
In all my years of looking at sailboats and sailboats for sale, thousands, I've never seen a motor with more than 6,000 hours on it. And I've only seen maybe 2 or 3 of those.
You can get a vibe of the overall aura of the boat. You can readily see if it has been cared for. Not absolute, but that care likely included the motor.
Your senses will tell you: Is it original paint on the motor and clean, fluids healthy, no or tiny smoke, good water flow, sounds like a diesel.
Concluding that it's nearly impossible to wear out an auxiliary diesel in sailboats, with a well-maintained motor predicted for a 20k hour wear life, if it looks good and sounds good, it is good.

 

[Charlie98117]

I have the same boat, same year and have wondered the same thing. Your engine looks much nicer than mine which has 3200 hours according to the meter that a PO installed. They seem to be a pretty bulletproof engine, I've heard 5-7K is reasonable to expect. You seem to have a great maintenance routine so I would think you could go another 30 years with no problems.

 

[Roland5048]

The tape on the intake is for winter layup

Thanks, that's what I thought but was not sure. We don't have that issue 'round these parts.

 

[pateco]

My 1983 H31 with the raw water 2gm 13hp. is still alive and kicking.