Yanmar 4JH3E Oil Cooler

[Chief Engineer]

Oi vey!!!!!!!!!!!!!

The point of Anchoring out is so people are not able to WALK UP to you.

KOA and other motor home parking pads are not my idea of adventure.

Plus you can't sail a motorhome ...home when the Main Engine QUits

Originally Posted by cetacean67

Thanks All,
I'm learning all the time, but unfortunately I haven't been able to get to my boat recently to check engine and/or the owner's manuals (long story). From what 'Chief Engineer' says we should all be checking for the presence of zincs or suitable bonding - I'm not sure Yanmar or the boat manufacturers stress this sufficiently.
I now have a new cooler fitted (at a cost of around £600), but I am not convinced that it is suitably protected even now. Even the 'professionals' I've spoken to seem pretty vague about these issues.
I'm thinking about swallowing the anchor and buying a motorhome - rock and a hard place or Frying pan to Fire?
Cheers, Phil

[cetacean67]

Originally Posted by poppyduc

I have a Hunter 41 4 years old and heading for same problem, I can't seem to stop the corrosion on the cooler and believe it has a very limited future.
How did you fix it or just replaced the part which I have been told will be very costly
Steve

Steve, sorry for the delay. I've had it replaced (big cost, £500 ish) but still haven't resolved whether it is likely to happen again, or whether it has an anode. I now have the boat locally, so will investigate myself and get it checked by a Yanmar agent. There is obviously a problem which needs sorting out. Hopefully, I'll know the full story soon.
Phil

[Vasco]

Well this is very interesting. I have the same boat as Mark with a 4JH3E. Got a bit concerned and since I'm in a boatyard getting my boat ready checked about the anode. The boatyard checked their online manuals and could not find a pencil zinc for this model. They then called Mastry, the southeast Yanmar distributer and were told that this engine does NOT have a zinc in the oil cooler. They suggested that it must be an after market cooler to have the zinc! Unfortunately I have the aft cabin full of crap so I can't get at the back of the motor for a look.

Mark, where exactly is the zinc? Which side is the oil cooler on?

[Vasco]

Here's what I found in mine. It looks like what's left of a zinc or is this just a plug? It was on the left side of the cooler, in a tube coming out of it. About 2.5 cm long. A 11mm nut. The Yanmar dealer says the cooler does not have a zinc and says it might be an after market cooler. The cooler looks like a Yanmar part, has no after manufacturer name or id on it. The cooler looks exactly like the one in the Yanmar parts manual except this tube with this anode? in it is not shown

[Chief Engineer]

That is a drain plug.

There is an inline zinc tou an put in.

You will need to cut the hose...install and hoseclamp and run wire to heatexchanger and block

[Vasco]

Thanks Chief, I've come to the conclusion that there is no zinc on my Yanmar oil cooler and that Mark has an after market cooler. This drain is in a long tube that looks as if it could take a zinc but I can't find a zinc this small diameter.

The tube is in the left side hose which I think is the "in" side of the water. I don't think it'll take a zinc as it bottoms.

[MarkJ]

Originally Posted by Vasco

Thanks Chief, I've come to the conclusion that there is no zinc on my Yanmar oil cooler and that Mark has an after market cooler.

I'm quite sure it isnt after-market. We had a genuine Yanmar mechanic who changed ours.

[Charlie]

Well this sure is an interesting discussion I have a 4JH4E and the manuals say there is no zinc. I will have to investigate further. Ok upon further investigation I have found in the manual what look like a zinc in the oil cooler.
When I figure out how to insert a picture I will show you the page in the manual.

The upper most left diagram has what looks to be a zinc on the upper right side. Could this be the elusive zinc?

[Vasco]

Charlie,

That's not a 4JH3E in your diagram, the 3E has one water inlet, left side, one water outlet right side, one drain on right side bottom and one drain on left side, rear, water inlet, not on the round cooler itself. The oil in and out are on top. I will take a pic tomorrow. Mark, I have asked you before, where is the zinc?? I checked my cooler and it is a Yanmar with the part number on the forward right side which is very difficult to see. Believe me I have been all over this engine in a very confined space. Yanmar insists that there is no zinc on a Yanmar cooler. They did say that some engines came with after market coolers. I want to get to the bottom of this so keep the posts coming.

[Charlie]

Rick your right this is a 4JH4E

[Kapitan]

Hi there guys,

As an authorised Yanmar service dealer I want to speak about the subject. The Yanmar engine 4JH3-E does NOT have zinc anodes.
The reason of your problem is weather you were using an old antifreeze or a wrong antifreeze. Be sure to use the antifreezes that Yanmar recommends and check out the condition of the antifreeze every season. Usually it is best to change it every two years.

If you had the problem, be sure to check the main cooler's housing too. It is possible that you'll see the affects of corrosion there.

Edit: The oil cooler uses fresh water to cool down the oil on this specified engine model

[cetacean67]

Hi Kapitan, I don't think my last attempt sent correctly. Thanks for clearing up this question. Do you know what the Yanmar antifreeze contains or does not contain to make it suitable? I have just been supplied with some from a Yanmar agent,but it was just a normal motor factor (Carplan) 5y type, fluorescent pink antifreeze. They said it was just as good and a fraction of the price. (Quote: 'Yanmar don't make their own antifreeze'). Could you enlighten us on this one?
They all seem to be about the same price as Malt Whisky, could we use that instead?
I'm still slightly puzzled though - the oil cooler that disintegrated was filled with raw seawater, not the fresh water + antifreeze mix. The suggestion from most people is that it must have been electrolytic action.
Thanks, Phil

[Kapitan]

Hello Phil,

I am extremely sorry that I've just mixed the engine models. Your lube oil cooler uses sea water to cool down the lubricating oil.

The cooling water system is of the indirect sea water cooled, fresh water circulation type. The cylinders, cylinder heads and exhaust manifold are cooled with fresh water, and fresh water cooler (heat exchanger) use sea water.

Sea water pumped in from the sea by the sea water pump cools the lube oil in the lube oil cooler and then goes to the heat exchanger, where it cools the fresh water. Then it is sent to the mixing elbow and is discharged from the boat with the exhaust gas. Fresh water is pumped by the fresh water pump from the fresh water tank to the cylinder jacket to cool the cylinders, and the cylinder head. The fresh water pump body also serves as a discharge passageway (line) at the cylinder head outlet and is fitted with a thermostat.

Yanmar does not make their own antifreeze as I know but advices brands and types depending on where you live. We are based in Fethiye/Gocek in Turkey and we use Castrol Antifreeze SF for the Yanmar engines. The antifreeze is pink and includes organic acids. It does not include silicate, phosphate, amine, borate or nitride. Its 3 liter package is sold for € 20,50 here. I don't know the 3 liter price far a good malt whiskey tough

The lube oil cooler material is brass (90/10 CuNi) except tubes. This is why Yanmar does not have any zinc anodes on the lube oil cooler.

I am a Materials Science Engineer and would like to enlighten you about the material. Copper-nickel has excellent resistance to uniform corrosion, remarkable resistance to localised corrosion in chlorinated seawater and higher erosion resistance than other copper alloys and steel. It is also resistant to biofouling. The cause of the failure is mostly attributed to the composition and production of the alloy, occurance of erosion-corrosion and corrosion damage in polluted waters.

In your case I'd suspect from the components of the cooler (manufacturing) and polluted seawater which is very common in harbours. There is very little to do to prevent this happening again if any.


Below you can find the Yanmar Service Manual advice on inspection of the cooler:

To inspect the oil cooler:
* Clean the inside of the sea water pipes with a wire brush to prevent the build up of saale
* If the rubber hose connection or welds are corroded, repair or replace the cooler.
* Apply the following water pressures to the sea water and lube oil lines to check for any leakage. Repair or replace the cooler if there are any leaks.

Lubricating oil circuit: 1,5 kg/cm2 (test pressure)
Sea water circuit: 4 kg/cm2 (test pressure)



Hope I helped

[cetacean67]

Thanks Kapitan,
A very thorough response. I'm surprised that there is little I can do to prevent this happening again, as replacing the Oil cooler is pretty expensive (4 - 500 £ or €). I'll be keeping an eye on it.
If all goes well, we may sail down to Turkey next Summer - so perhaps we can discuss further over a beer.
Cheers, Phil

[Kapitan]

You're mostly welcomed. If you have any more troubles with your engine or any other equipment on board please feel free to ask to me directly. I'd like to help you out anytime.

Sailing in Turkey is really great, I'm sure you'll going to enjoy from the beauties of our coasts and services as well.

I'd love to meet and talk to you on a warm Fethiye afternoon enjoying a nice cold beer

Cheers mate, Cem


PS: I wonder the price of the cooler here, I dont have the Yanmar parts catalogue at home but when I go to the office tomorrow I'll check it out and tell you the price here as well