Good Grief! I mean *&%)$#@!

[Roger Long]

Another engine drama begins and the prospect of a winter shoveling snow looms.

I noticed that the engine smoked a bit more than I would have expected yesterday with an inch of pitch just taken out of the prop. I checked the liquid trap in my crankcase breather line and found it nearly filled with the gray mousse of emulsified oil. That was strange because the trap has stayed clear and not even needed to be drained since Cape May.

I next checked the dipstick and found the oil level way up. My heart sank a lot farther. I've only run about 10 - 15 hours since the last oil change and I know the level was right on. I slightly under filled it and then topped it right up to the mark the next day.

I pumped some oil out. The engine was cold and I can usually barely move the pump piston with cold oil. The engine has to be piping hot for an easy oil change. The oil flowed out like water. My heart sank further.

The good news is that the oil I pumped out doesn't appear to have any water in it, even after sitting for an hour to separate. That means my raw water cooled block probably hasn't rusted through yet.

Two prime suspects now. The most likely cause and the easiest fix is a failed rubber diaphragm in the mechanical fuel pump. However, I have a pressure gauge on my fuel system to alert me to filter load up and it hasn't gone down a bit since yesterday.

If fuel is going past the piston rings, the engine will be coming out of the boat and I won't be going south this year.

There are some other possibilities, such as injector pump gaskets, etc. At least this is happening when I'm in a marina slip and not planning to go anywhere for a while. I'll do an oil change and take a look at the fuel pump tomorrow. I'll swap in the old one that was working when I replaced it proactively. Since I always run with the electric pump on, I'll probably by pass the mechanical pump completely and see what happens with further running.

Stay tuned.

 

[Snotter]

Perhaps it would be fruitful if you tested the oil with one of the oil-test kits such as the one sold by sailorsolutions.com.

http://www.sailorssolutions.com/index.asp?page=ProductDetails&Item=EC01

 

[Rick I]

Hope it's the common problem of the lift pump diaphragm leaking.

 

[kloudie1]

It takes a good bit of leakage to raise the level in the crankcase.. I feel like Rick does .. it is probably the diaphragm in the lift pump.. When ya test, be sure the mechanical pump is isolated so the electric one doesn't put fuel through the same hole in the diaphragm.

 

[Roger Long]

Oh (pre-deleted by moderator, pre-deleted by moderator, pre-deleted by moderator, pre-deleted by moderator, pre-deleted by moderator, pre-deleted by moderator, pre-deleted by moderator) I mean really, really pre-deleted by moderator.

I just drained out the oil and removed the mechanical diaphragm pump. Not a hint of leakage blowing air through it hard. Disassembled and the diaphragm looks perfect. The fuel is coming from somewhere else.

Two possibilities left that I can see. Worn piston rings or some kind of seal failure in the injector pump that is letting fuel in through it's drive system. The engine starts briskly and runs well. It didn't burn any detectable amount of oil until just about 150 hours ago so it's hard to believe the top end is worn out.

If it is the injector pump, it's still a big job (if I can get one for an engine of this age) as timing it will be hard to do in place with my installation.

I don't see a very high probability of my posting from points south and the ICW this year. It's more likely that I'll be selling or giving away a boat without an engine. I'm in less of a position to re-power this boat now than I was back in Solomons.

I wonder if the first place I ever anchored on a cruise in Maine will also turn out to be the last:

http://forums.sbo.sailboatowners.com/showthread.php?t=144485

 

[weinie]

Roger,
I'm no expert, but could a stuck needle in an injector cause fuel to leak into the cylinders while you were on the hard?

 

[Bill Roosa]

Hey Roger. first things first. It's your freekin A-Frame going bad!!! Gona cost you a million buck cause the EPA has to certify all work. They will not even let you sell the boat in that condition. Panic now and get it out of your system. We'll wait.

Ok now that we have that done I'd recommend changing the oil and run the engine for a while keeping an eye on it.

 

[Don12364]

Something doesn't ring true

Roger,
You are concentrating on the possibility of fuel getting into the oil.
This is based on not finding any water in it and I hope that is the case.
But how does one account for the water trap in the crankcase breather line being "full of a grey mousse of emulsified oil"?
It is very rare for more than one fault to occur at a time.

 

[anchorclanker]

Donalex is asking the right question. diesel in the oil shouldnt turn the oil gray. The worst ive seen, a ford diesel tractor was pumping about a quart per hour of fuel into the crankcase from a broken return line under the rocker cover. The oil got thinner and oil pressure dropped, but it remained clean.

Grey or cream colored generally indicates water in the oil. Could be a blown head gasket, among other things.

 

[Benny17441]

Water emulsified with oil will not easily separate without the aid of chemicals so do not eliminate the possibility of water. Your best indicator will be the color of the oil in the crankcase as the emulsion will take a light gray color. On the other hand a mix of diesel fuel and oil will not render much of a change in color and would have a strong fuel odor. If it is water check the head gasket.

 

[Roger Long]

But how does one account for the water trap in the crankcase breather line being "full of a grey mousse of emulsified oil"?

Donalex is asking the right question. ....a broken return line under the rocker cover.

The very small amount of liquid that has been collecting in the return line since I was in the Chesapeake has been grey emulsion due to normal water condensation on start up. A small amount collects during the first few minutes of running and crankcase discharge is then just clear vapor. The heat has been evaporating the little water that collects so I haven't even needed to drain the water trap.

Post oil change operation was just a few short runs so there would have been more than usual condensation in both the water trap and the oil. When the fuel leak raised the oil level, the crankshaft contacted the oil and whipped it up. The foam went out the breather.

There was absolutely no sign of emulsion or froth in the oil I pumped out of the sump. The only place I have seen any evidence of water is in the breather line. I just looked at the oil that has been sitting in a clear container all night. It looks just like oil only thinner. No sign of any separation at the bottom of the container.

I'm pretty sure all my fuel piping is outside the rocker cover but I'm going to study the manual and take another look at the engine this morning.

I just ran across this rather depressing account of someone dealing with the same problem on the same engine:

http://www.sailnet.com/forums/diese...8-yanmar-2qm20-fuel-oil-gear-maint-forum.html

 

[anchorclanker]

I see what your saying more clearly now, yes, a fuel leak would do that.

If its not the lift pump, its almost certainly the injection pump leaking internally. Ive read a lot of your posts, and you appear to have a great deal of mechanical knowledge. Probably if you had a good exploded view diagram of the pump along with a service manual you could probably fix it yourself, its probably the plunger packing (im assuming yanmar/kubota). You would have to remove the pump and remove the plungers, etc., replace packing.....

However, you could also call a local diesel injection service garage and they could likely order you a pump, or you could find one online. The pump should have a metal tag riveted to the body with a part number, that should be all you need and would probably be the cheapest and quickest fix outside of trying to repair the pump. Ive seen rebuilt pumps anywhere from $250 to $500, plus core. A tractor dealer may also have the part, or could match it. Then you only have to set timing and adjust idle/no load and your back running.

 

[kloudie1]

Thinking out loud.. only a couple of places where that much fuel could get in the crankcase without causing some gross running problems.. The lift pump diaphragm and where the diaphragm connects to the actuating plate. If you can pressure test by putting 5-6 psi on the diaphragm with the pump out of the engine, that would be a way of eliminating that possible cause.. maybe pull the pump then hook up to the electric and pressurize while moving the actuating link.. The injection pump is the other place, the low pressure side .. There is a gasket or seal that they call the "plunger barrel packing" that would (if failed) allow low pressure fuel into the crankcase. It is not clear from the drawing that I have if this is a copper gasket or an elastomer .. That piece is not plainly shown or noted on the cross section drawing.. There is a note in the book that says that the packing is a place where fuel can get into crankcase oil.. Another thing that could leak to crankcase would be a small crack in the high pressure pump body where the low pressure fuel is admitted into the plunger.... This is least probable in my opinion.. The injection pump could be checked by pulling the pump and pressurizing with the electric one to 4-6 psi and looking for fuel drooling.. Hope ya find it..

 

[Roger Long]

If you can pressure test by putting 5-6 psi on the diaphragm with the pump out of the engine, that would be a way of eliminating that possible cause..

I've done that. I put soap solution into the actuator lever cavity and blew as hard as I could while moving the lever. Nothing. If it's airtight at maximum breath pressure, it should be fuel oil tight.

On to the injection pump.

I'm going to put the mechanical pump back on but bypassed, refill the engine with oil, and run a while to gather further data. I also need to get the boat running in case of a storm or to move it to where a mechanic can check the compression just to rule that out.

 

[anchorclanker]

You could check compression, but IMHO thats likely not where the problem lies. Ive seen some with compression so low they were hard to almost impossible to start, and smoke and use oil, but they still didnt dump excessive fuel into the crankcase. Old Detroits can be so sick they need half a can of ether to start on a 90 degree day, they just use more oil, lol, like a gallon per 75 miles!. I had a 300D once I pulled out of a farm field, we pulled it for over a mile at almost 40 mph to get it running, but once it was running, it ran fine. If they have enough to start, they have enough to burn everything they can get.

I think like you, a crack in the pump is unlikely, but regardless, if its not the lift pump, you have to pull the IP.

 

[kloudie1]

Sounds like you are heading in the right direction, Roger. That should tell ya if it is the IP.. Good luck with it.. Looking at the manual, the IP doesn't look to bad to mess with but everything seems to be very critical .. There should be a local diesel injection pump guy who can fix ya up ..
EDIT: Looks like the fuel inj. timing marks are on the front pulley on that engine.. I hope you don't have to re-time, but it should be accessible if ya do..

Edit 2 : I think that barrel packing is : http://shop.torresen.com/ships_store/index.php?p=details&mfc=Yanmar&sku=124950-51270
May not be the correct one, but Torresen should know..

 

[Benny17441]

Misled by the attempt to separate water out of the oil. It can be said now the problem is fuel. No sense in speculating, continue to run diagnostic tests to isolate the problem. eliminate the lift pump as a potential cause and move on to the injection pump. Fuel leaking through the rings seems unlikely in an engine that is running well.

 

[Jake N Eggs]

Hey Roger, If you have to remove the injection pump and it is gear driven then the timing is probably a rotational component of the mounting flange. Before you loosen the pump mark the pump housing and the engine block or front cover with a sharp chisel in a way that you can line the marks up exactly when the pump goes back on. It will save you some future timing grief. This is assuming that the same pump goes back on.

Good luck.