2000 Yanmar 4JH2-HTE with 134 Hrs

[Thebaysailor]

I have the same engine, 1996. I recently inspected the exhaust elbow, bronze, to fix ND it was in great condition. This let me look at the turbo. It was locked up with corrosion and required a tear down and rebuild here in Florida. Cost $700.

[SofaKingFishy]

Originally Posted by ljrthughes

Hello, Yanmar enthusiasts! I am purchasing a sailboat with a 2000 (mfg year) Yanmar 4JH2-HTE that has 134 Hrs on it! The engine has not been rebuilt, routine service only, and is original to the boat. It looks like it has been well-maintained, and the boat is immaculate. I'm having an engine inspection done by a diesel mechanic but, I am worried that an engine with such low hours, sitting most of the time for 23 years, will have issues like oil seals and possibly internal corrosion. I had the same issue with a Lycoming engine on my airplane which resulted in a $11,000 cam replacement. Any ideas as to what I should request as part of the engine inspection?

I owned this engine for 4 years—check the coolant system for leaks at the gaskets. The cover is aluminum, and has a tendency to fail. Cost is about $1200 for parts.

[DreamWeaver III]

Originally Posted by ljrthughes

Hello, Yanmar enthusiasts! I am purchasing a sailboat with a 2000 (mfg year) Yanmar 4JH2-HTE that has 134 Hrs on it! The engine has not been rebuilt, routine service only, and is original to the boat. It looks like it has been well-maintained, and the boat is immaculate. I'm having an engine inspection done by a diesel mechanic but, I am worried that an engine with such low hours, sitting most of the time for 23 years, will have issues like oil seals and possibly internal corrosion. I had the same issue with a Lycoming engine on my airplane which resulted in a $11,000 cam replacement. Any ideas as to what I should request as part of the engine inspection?

It's only just run in 100hrs is nothing. Run it like you stole it in the sea trial, look for smoke - black or white (signs of possible different problems) and lots of cooling water - you could go down the route of an engine servey but if it runs smooth (for a diesel) isn't sluggish doesn't blow smoke chances are it's mint, oil, filters, impeller and mixer elbows can be classed as consumables - replace and enjoy

[ljrthughes]

Would this work for the Hunter poly fuel tank?

[ljrthughes]

Okay folks,

Sorry for the abscence. We were working overtime on boat projects in Southern California trying to get the boat ready for a passage up the West Coast to Oregon (November to March). We finally had a window in March and made the passage without any big issues. Heres a follow up on what we did. I took the boat to a diesel fuel specialist who polished the fuel and cleaned the tank. He said the fuel and tank were dirty, but he has seen way worse. We also changed the water separator filter and the fuel filter after all was said and done. We motored 5 days up the coast and settled in at Crescent City. No fuel issues 🙏 ! We still have to install a fuel inspection cover. I have been working on some residual issues with engine maintenance including inspecting the heat exchanger and turbo. The heat exchanger has some scale buildup bu the metals look good with no internal corrosion. The turbo looks great, other than some external rust. I don't see any exhaust leaks and the internals have no play in the bearing/shaft. The blower and turbine fins look good. There is some rust build-up where the turbo meets the exhaust mixing elbow. Do I need to worry about this?

[ljrthughes]

Heres a pic of the turbo exhaust...

[skipperpete]

That turbo photo ain’t showing good things, that much corrosion at that location means that either the mixer has failed or the exhaust system has a design flaw. I guess its possible for the corrosion to be caused by the humidity created by the pond of raw water in the aqualock but it looks worse than just the usual humidity damage, the fact that there’s corrosion between the gasket and the turbo housing isn’t encouraging. Those 3 bolt lightweight injection elbows have a very short life and if that corrosion extends into where the turbine is, you’re not far off from experiencing a stuck turbo

[hugosalt]

Originally Posted by ljrthughes

Would this work for the Hunter poly fuel tank?

If question is would the inspection/access panels I suggested up thread would work...I installed mine on plastic tank and very happy.
Can look at Boyd Welding web site.
They come in 2 sizes each in aluminum and SS .
Think? Aluminum pricing $40.small /60 large.

[ljrthughes]

Great, I will give the welding company a call for the inspection cover. As far as the turbo goes, I have not yet removed and inspected the mixing elbow. Maybe I will contact my local marine mechanic and have them look at the turbo & mixing elbow. The connection at this point is a low spot so I think it’s just a collection point for moisture when the engine is off and begins to cool.

[ljrthughes]

Follow up:

I cleaned up the rust on the turbo where it meets the mixing elbow (also inspected). I gently broke the built-up rust (as shown in the picture) which was from the degraded metal gasket. When all was said and done, the resulting surface was as good as new. The mixing elbow was also in perfect condition with no corrosion. I assume the rust was just bulit-up from residual humidity after the engine shut's down, as someone in the previous post mentioned.

The next step is to install the fuel tank inspection cover and cut a removable lid in the port aft lazaret cabinet floor (to access the top of the fuel tank).