New Yanmar catastrophic failure

I bought two new Yanmar 4JH57 a few years ago. Installed them in the catamaran i was building. They got turned over for few seconds every few months.

Just launched the boat last week

One engine was blowing mist of sunburnt diesel, cylinder three identified as the culprit. So i got injector cleaner and checked, replaced it and started engine.

White smoke, unburnt diesel again

Nudged revs up a bit

CLATTER CLATTER BANG

This is a dead engine, I felt sick, what a fool

Then this morning im thinking, this cant be right, new unused engines

Anyone else had this happen?

 

Rather than just turning the engines over for a few seconds every few months, it would probably have been much better if you could have hooked up a cooling water supply to them and run them up to operating temperature each time every few months?

Re the 'clatter bang', did an escaped con rod punch a hole in the block, or?

 

That's too bad @MichaelRoberts .
At what RPM did it let go?

 

Diesel fuel aged and got gunky?

Ruined the high pressure pump and more after running metal into it?

All conjecture, but see if the fuel is bad.

 

Water in the fuel, check fuel filter bowls first of all.

 

Please let us know how this plays out. Most warrantees have a constructive use provision, so the warrantee doesn't start until you actually put the thing into operation. While I think what you said you did was not a good idea, I don't think it should cause a catastrophic failure either. You need to document everything you can, show that there was oil and coolant in it at the time, take pictures of it as it sits, and be very persistent. They aren't just going to give you a new one. They will say no, no, no, no, okay - don't tell anyone. Keep ramping up the pressure on them, but be professional. Very occasionally, you just get a lemon right out of the box.

Also, I'd have the sales rep send someone out to look at the second engine and help get it broken in.

 

Did you try manually turning the engine with the thing in a no start?

Maybe the noise is the fuel pump?

 

Keeping the engine oil warm and circulating it frequently will keep a stored motor in ready to roll condition.
Fuel stabilizer may have helped,
Let us know how this works out, I’m curious about the failure mode.

 

sounds like hydraulic lock, in fact bet my boots on it

 

What would the failure mode look like? Most everything I’ve hydro locked wouldn’t crank. But I suppose if the other cylinders drive, then bent or broken rod. And what would have caused a leakdown in a new engine?

 

depends if the engine exhaust was open to the sea, if not then only other thing would be jacket water leak fro head gasket

 

@MichaelRoberts seems to have lost interest in this thread already - he has not logged in since his initial post on Monday.
Mike, if you are reading this without logging in, please do log in and offer some answers to the various questions above.

 

Could be he's busy "licking his wounds".
Thinking you've lost an unused, "new" engine would be misery.

 

Well, His is not the kind of problem that’s easily resolved by internet posting, so hopefully Michael Roberts is up to his greasy elbows in disassembled Yanmar parts by now, and will be posting results with pictures as soon as his hands are clean enough to touch a computer keyboard again!

 

What about a fuel leakdown?
Says he was spewin unburnt diesel.

I have a riding mower that fuel leaks down from the carb if we don’t shutoff the gas is all.