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Discussion Starter · #1 ·
Here I sit in a marina in France BR's engine in pieces. Why, you ask? Salts in the oil.

Prior to the trans-lant last summer I re-powered the boat. Out went the 18 yr old 55 hp Nanni, in came the new 110 hp Yanmar. (Note the boat's designer indicated we needed at least 90 hp, so the first owner obviously underpowered her.)

As we will sell the boat sometime in the next 5 yrs or so I decided to have an oil analysis done with each oil change. I took a sample at the 50 hr oil change in Newfoundland, and another when I laid up the boat in Scotland last September at 280 hrs. I forgot to take the samples home with me and the first opportunity to send them to the lab was in the luggage of a departing crew member several weeks ago.

Lab reports came back: first oil sample had small amounts of sodium and potassium in the oil. The lab was curious. The second sample (taken at 280 hrs) showed a very large increase in the amount of sodium (5200 ppm) and a similar increase in the potassium. Lab said -- no doubt something is leaking into the oil. They said it could be seawater, or it could be coolant. "Find the leak" was their recommendation. Salts in the oil were causing accelerated wear of critical bits of the engine -- and the metal content of the oil samples was also well above normal.

I'll stop here for an important digression: without the oil analysis I would have never known this was going on. The engine runs perfectly, aside from a bit of soot on the transom. I would have continued motoring along (when not sailing) fat, dumb and happy and, because I plan to sell the boat, it would have been the next guy's problem because the excessive wear of bearings, etc. would probably not shown up as a real problem for a while. But I do have the oil analysis and so it's my problem. :(

So, the question is what to do?

First step was to call the Yanmar guy here in Brest, France. He's a nice man in his late 50's (that's good -- means he's experienced), and he speaks some English (that's also good because I have only high school French and a copy of "French for Cruisers").

He comes aboard last week and the first thing he does is take another oil sample. His examination of the oil on the dip stick and inside the valve cover suggests to him that it's not water. He said, "The oil is beautiful". First time I've heard someone call dirty 150 hr engine oil "beautiful", but this is France and things are different here.

So far we have removed the oil cooler and pressure tested it on the bench at 80 deg C. It's good, no leak there. The oil analysis requested last week came back today and we continue to have sodium and potassium at elevated levels. So there's a leak somewhere.

The question I have for the gathered mechanical cognoscenti is what course of action do you think we should follow from here? What are the potential sources of a leak of either seawater (minimal probability) or coolant (likely) leaking into the oil.

All though I have confidence in Philippe, our local Yanmar guy, your sage advice will be welcome.

I will conclude by saying that it's true -- cruising is defined as working on your boat in exotic places. While Brest isn't exactly "exotic" the food is very good, the cheap wine very good, the bread excellent and the cheese very smelly. What more could you ask for? :D

PS -- I forgot to mention: we had an overheating incident at 10 hours when the main alternator belt came off while motorsailing. Engine was shut down immediately (like within 10-15 seconds of the alarm), but the temperature gauge indicated 250 deg F / 120 deg C. Motor has worked flawlessly ever since. And I should add, we have had no over-cranking incidents -- the engine starts immediately, as a very expensive Yanmar should.
 

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Discussion Starter · #10 ·
I am also a believer in oil analysis however most of the ones I have used are detailed enough to distinguish between saltwater or coolant intrusion. The company I use most often is Blackstone Labs. After checking all of the basics on your engine I would look at sending your oil somewhere else for a more detailed analysis. I do agree that it is almost certainly coolant though. If it were saltwater you would see mostly sodium but not much potassium. How are your phosphorus and boron numbers? These are also indicators of coolant leaks. There are a couple other elements too but I can't remember them off the top of my head.
Blackstone did the analysis and leans toward coolant, but wasn't 100% sure.
 

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Discussion Starter · #11 ·
Oil analysis came back today with ongoing sodium intrusion. French lab thinks it's a coolant leak. This seems to be confirmed by the pressure test we did today on the cooling system. Results of that are: pressure starts off at 1 bar, and drops fairly steadily over 1 min. or so to 0.75 bar and then it stabilizes. This suggests a small leak that gets worse under pressure, n'est-ce pas?

We're waiting on a confirmation of delivery go the gasket set which we ordered yesterday. First guess by the supplier is Monday, maybe Tuesday next week. I could fly to Holland and pick them up for less than what another week on the dock will cost....I just may do that.

The mechanic is reluctantly saying that it's "grand chose" (big stuff) and may take 4-5 days I'd wrench work to replace the exhaust and head gaskets. Lot's of stuff has to come off to get to the problem.

If this goes on too long I may need to think about moving on across Biscay while the weather is good.

Need some input from the obviously knowledgeable responders above: Will frequent oil changes, say every 50 hrs or so minimize the damage until we reach another long term stopping point? Or should I suck it up and fix it here and develop cruise plan B?
 

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Discussion Starter · #24 ·
Many thanks to those who have responded with suggestions.

An update:

We went on across Biscay. We had the right weather and crew was available, so we changed the oil and did the crossing. I thought I could get it fixed in NW Spain, La Coruna. Mechanic there said he didn’t have time and referred us to the regional distributor in Vigo further south.

On arrival in Vigo several days later the Yanmar service supervisor and his mechanic were aboard and did a 45 minute very thorough visual inspection of the engine. They looked at the oil on dipstick and did swipes of oil on the top of the valve cover. They could find nothing wrong with the oil, and no indicaton of oil in the coolant. (Recall the French mechanic called the oil “beautiful”, these guys felt the same way). They aid there was no (visual) sign that any liquids were in the oil. They traced the cooling system looking for leaks and found none. Their conclusion: there was nothing wrong with the oil, the coolant or the engine. I got the sense that if they were from NJ they’d have said, “Fuggetaboudit”!

“But what about the lab reports”, I countered. They took copies and said they would send their write up (I have a copy) and the reports to the Netherlands Yanmar European HQ for comments/suggestions. I’ve heard nothing so far.

So, we continue on our path south and are planning on changing the oil every 40-50 hrs and continuing the lab tests.

I’ve started a very close monitoring of the coolant levels and for the last four times we’ve operated the engine I’ve seen virtually no drop in the coolant bottle (maybe a 1/6th inch--about the thickness of the mark I made on the bottle.

I have all the parts we need to do a complete tear down of the block, but I can’t seem to find a Yanmar mechanic who wants to take my money. We’ll keep trying as we move south. We have a 10 day stop in Lagos in southern Portugal and perhaps we will have word from HQ gurus by then.

If we were in the US near the guys who installed the engine and had access to all the high tech tools/methods described in some of the posts above I’m sure with time and money we could nail this problem down, but for now, the realities of long distance cruising in foreign lands prevail and we just have to keep moving so we’re positioned in November for the trade winds crossing.

I’ve had a couple of ideas that you might comment on:

1/ the engine is turbocharged and has an air cooler (seawater cooled). A small leak there could put small quantities of seawater in the intake air. The water would be vaporized in combustion and salts left on cylinder walls to find their way eventually to the oil.

2/ the rough seas we sometimes experience could be sloshing water from the muffler up the elbow. I doubt this as the installation team at NEB Portsmouth are very professional and I doubt they would not have engineered the exhaust system correctly.

3/ I wondering if my operating methods have contributed....we have a Gori prop (with overdrive) that allows us, when motoring in flat seas, to reach near hull speed at 2200 rpm (vs say 2800-2900 with the normal pitch). I’ve used the overdrive a lot (when fuel is $8 / gal one looks for savings where you can find them). The lower rpm reduces the pressure in the exhaust system and may allow a larger quantity of water to remain in the muffler when the engine shuts down. Follow that with sailing in heavy swell / rough seas (with engine off) and we may get the sloshing up into and beyond the elbow????

Will continue with updates when available.

Thanks again for the help thus far.
 

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Discussion Starter · #37 ·
A couple of quick responses....

1. There's no sign of "mustard" or "chocolate milk" oil.....it's clear. I know what that's like. Had a hydraulic lock once with the old engine after a 21 day passage in the trades. Five gallons of chocolate milk in the oil pan. I now start the engine once a day while at sea.

2. I have given up the overdrive for the time being. We'll run with standard forward pitch until this issue is resolved.

I've scheduled an appointment with the Yanmar guy in Lagos, Portugal. I'll post another update following that encounter.

Changed the oil at 50 hours today. Thank god this engine uses only 5 liters. The old six cyl. Nanni used 5 gallons.

Thanks again for the helpful advice and suggestions.
 

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Discussion Starter · #46 ·
What caused this? Was it a following sea coming in through your exhaust? How did it get in the oil, and how would starting it once a day prevent this issue?

MedSailor
For 15 days we had big (15+ ft) swells hitting the stern every 15 seconds. Eventually it pushes enough water up the exhaust to fill the muffler. From there it moves up to the exhaust elbow and then into the cylinders with exhaust valves open. After a while I guess the water in the cylinder makes it's way to the oil sump where when mixed with the oil by boat rocking and rolling the oil looks like chocolate milk.

While it may only take one wave to fill the muffler, my guess is that it takes a bit longer. My theory is that by starting the engine every day we blow any excess water out of the muffler and thereby reduce the probability of water finding it's way into the engine.

The morning of our arrival in Sint Maarten in 2000 we tried to start the engine. Turned the key and nothing happened. We quickly checked the battery and found it OK.

We were lucky that we had one cylinder completely full and so the engine was "locked". Had we had only an inch or less in one cylinder the engine might have started to turn over. As water doesn't compress very easily :) something would have to give....usually internal parts get bent/break. So, if this is gonna happen to you, pray the cylinder is completely full so the engine won't move at all.

I won't go into all the gory details of how you do the repair, but it's messy and you end up having to change the oil at least three times before all the water is gone. Once all the water was gone, the engine worked well for another dozen years. Only problem the water intrusion is that it corroded the effected cylinders just enough that it eventually caused was a drop in compression in the two cylinders where water got in. By 2006 pressures in these cylinders were down significantly but still above factory spec minimums. The problem was the differences in pressure between cylinders was out of spec.

The engine still worked well and was reliable, but it was wearing out faster than it would otherwise. The other problem the excess corrosion in these cylinders caused was over pressurization of the sump. As gaskets got older the excess pressure started small see pages of oil into the bilge. Oil diapers needed changing regularly and the lost oil needed replacing. A nuisance -- yes, but not a major issue unless you're about to go cruising for an extended period and you don't want to be nursing a 20 year old engine in foreign ports.

That's when you go out and spend a small fortune re powering your boat....so you don't have to be dealing with mechanics whose language you do not speak.

I'll stop there before I start crying again. :(
 

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Discussion Starter · #48 ·
Any possibility that the fuel tank vents are allowing salt water into the tank that may be getting past the filter/separator? Curious to know if the analysis shows a little or a lot of salt in the oil?

Paul T
Fuel vent is on the stern about 2 1/2 ft above the waterline. Possible, but no water has shown up in the fuel water seperators (there are two between the tanks and the engine fuel filter) and the water alarm in the engine fuel filter has not gone off.

Re quantities of salt (sodium):

Sample 1 with 63 hrs on the oil was ~ 250 ppm
Sample 2 with 215 hrs on the oil was ~ 5200 ppm (end of season, after the crossing)
Sample 3 with 85 hrs on the oil was ~ 840 ppm

First two were by Blackstone, the third by a French lab.
 

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Discussion Starter · #59 ·
UPDATE:

When we arrived in Lagos, Portugal I invited yet another Yanmar mechanic aboard for a consult and another oil analysis in a local lab, results of which aren't back yet.

Since the last oil change I've stopped using the Gori overdrive and have been tracking the coolant level religiously.....in 50 hrs we're down only 1-2mm in the overflow bottle. The mechanic says that's not unusual.

Conclusion: it's not a coolant leak.

If it isn't coolant, it's got to be seawater. There are three sources of seawater: the oil cooler, the air cooler and the exhaust system. We tested the oil cooler and it's good. That leaves two possibilities.

The mechanic in Lagos took a hard look at the exhaust system and he thinks the problem may lie there. I have since done an analysis of the volumes of the hose runs and the muffler and have reached the conclusion that he's probably spot on.

When the new engine was installed it required that we increase the size of the exhaust lines from 2.5 to 3 inch hoses. The larger hose was stiffer and required installation of hard fiberglass elbows in a couple of places where the turns were tight. With those exceptions, the general layout of the old exhaust system was followed in terms of the hose runs.

Exiting the exhaust elbow we now have a 90 deg elbow and then 20" of hose to the water lift muffler (side in, top out). We have a 28" vertical rise coming out of the muffler to a 90 deg elbow and then a 5+ ft horizontal run aft to the steering compartment where the hose loops up to the top of the space and then drops to the exhaust port on the transom. In all, there is probably 9-10 feet of hose between the top of the muffler and the highest point in the exhaust hose run plus the ~ 2 feet between the exhaust elbow and the muffler.

The new engine was actually smaller than the old one (despite the ~2x HP) and so the height differential between the exhaust manifold and the muffler has decreased by a few inches, and due to the new 3" very stiff hose we need for a 90 deg. elbow immediately below the exhaust elbow -- all of which means that the angle of the hose running to the muffler is much shallower than with the old engine. My estimate is that it's a 8-10" drop from the exhaust manifold to where the hose enters the muffler, and that the hose is 10-15 deg off horizontal.

Less height differential + shallower angle = higher potential that we end up with seawater in the hose between the muffler and the engine IF the muffler fills with water when the engine shuts down.

Enter the new 3" hose -- larger diameter = greater volume of water in the hose and greater chance that the muffler has more water in when the engine shuts down.

Based on the calculations I've done of the volume of the hoses and the volume of the muffler, and using assumptions for the gas to water ratio in the hoses provided by Centek and Vetus tech support (Estimates range between 25 and 50%)....I've come to the conclusion that the muffler is overfilling (it should be no more than 1/2 full after shut down according to the tech guys).

Over filling the muffler puts standing water in the hose between the engine and the muffler when the engine is shut down. Now put the boat in a big following sea like we had crossing he Atlantic last summer and you now have water sloshing about in the pipe between engine and muffler with the potential for a few sloshes pushing small quantities of water up to the top of the exhaust elbow and into the exhaust manifold and from there a few drops get into the cylinders with open exhaust valves. It doesn't take a much water to register ppm of salts the oil. It's certainly not enough water to interfere with the starting of the engine. And, of course, once the engine starts the few droplets of salt water are immediately evaporated within the cylinder and hence no sign of foreign liquid in the oil.

So, the current hypothesis is the salts are from seawater entering the engine through the exhaust due to overfilling of the muffler, caused to long hose runs and larger hose.

With the approach of the fall season I need to move the boat further south and so we will not have time to address a redesign of the exhaust system before moving on from Portugal. We're moving on to Morocco next week (only 200 miles) where tech support and suitable parts are probably in short supply. We have some down time in Morocco and , my interim solution will be to install a small ball valve in lower part of the muffler which will enable me to drain the muffler into the bilge after shutting down the engine when at sea. I'm also going to install a flapper on the exhaust as a preventive measure until we sort the entire system out.

We will run with these two changes to the system and continue to change the oil every 50 hours until we can be sure that we've found the problem. My guess is that draining the muffler following every engine shut down will solve the problem....but that remains to be seen.

Stay tuned.
 

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Discussion Starter · #63 ·
If I am reading this correctly, you have no riser connected to the exhaust manifold? I made this same mistake when I replaced my exhaust system. Last year I added the riser and have not had an issue since.
Good idea, but no room for it in the engine space. A large day tank sits directly above the exhaust elbow.
 

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Discussion Starter · #64 ·
Test for inorganic chloride. This can be done by any of several simple methods, including test tapes.
I'll see if I can find these in the souk in Casablanca. :rolleyes:

One of the challenges of cruising in far away places is that many of the resources we take for granted in the US are, if not unknown, quite often unavailable.
 

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Discussion Starter · #66 · (Edited)
It has been an interesting thread. I come away from it thinking the engine needs a riser, and that the head gasket narrowly missed failing from the overheating. Maybe because the engine is new, but anyways, torqueing again the head bolts, wouldn't hurt. If just one bolt needs 10 more pounds of torque, it would be worth the effort.
I've mentioned torqueing the head bolts to three Yanmar mechanics in three countries. They all said it's not necessary. I point out to them that the engine's op manual suggests it. They just smile and shake their heads.

It's been very strange, but all the mechanics I've dealt with have been reluctant to take my money. None have wanted to tear the engine apart looking for leaking gaskets or even loose head bolts. I think it's like doctors not wanting to over-treat the patient.

A leaky head gasket would lead to coolant loss. As I mentioned above, I've been watching the coolant level very closely for the last month. The amount of coolant consumed by 50 hours of operation is a fraction of an ounce and all the mechanics encountered so far tell me that amount of coolant loss is not significant. Evidence suggests it's not a coolant leak.

As for a riser....we'll have to try the easier solutions first. Creating space for a riser would require a big reconfiguration of the engine space (moving the day tank, raw water and fuel filters, fuel pumps, etc). I'd like to exhaust the simpler (and cheaper) alternatives first and use frequent oil changes to minimize the damage to the engine in the mean time.
 
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