Yanmar Woes

[hpeer]

Boy, would I like to start a poll here on what the problem will be.

1 - turbo
2 - exhaust elbow
3 - fuel filters
4 - other

[bstreep]

Just another simple thought, because we have had this problem - that's a big engine with a large fresh air requirement. Getting enough air?

[Sailmonkey]

Originally Posted by bstreep

Just another simple thought, because we have had this problem - that's a big engine with a large fresh air requirement. Getting enough air?

Along this line, will the engine run up fine without the air cleaner and make a strange noise and lose power with the air cleaner?
I've actually seen the filt lining in a silencer for a turbo swell with oil and reduce the air flow enough to reduce engine power, increase exh temp and cause turbo "barking", granted this was on an 8000hp MAK engine driving the cutterhead on a dredge barge.

[Dockhead]

Originally Posted by bstreep

Just another simple thought, because we have had this problem - that's a big engine with a large fresh air requirement. Getting enough air?

Yes, we thought about this. Left engine space doors open but it didn't help.

[Dockhead]

Originally Posted by Sailmonkey

Along this line, will the engine run up fine without the air cleaner and make a strange noise and lose power with the air cleaner?
I've actually seen the filt lining in a silencer for a turbo swell with oil and reduce the air flow enough to reduce engine power, increase exh temp and cause turbo "barking", granted this was on an 8000hp MAK engine driving the cutterhead on a dredge barge.

The air cleaner is just a mesh with no element of any kind. But I'll try running it up that way.

[Dockhead]

Update:

I changed the fine fuel filter and switched the dual Racors to the other side.

There was some debris in the fine fuel filter, but no water. How the debris got past the Racors, I don't know.

The oil was overfilled. I removed half a liter of oil to bring the level down.

Then I motored for more than an hour at 2800 RPM, which is above my usual cruise RPM of 2400 to 2500. The engine was performing completely normally.

Can it be that all this hassle is from an overfilled crankcase? I topped up the oil in Cherbourg before departing on the trip during which the problem occurred. I seem to have overfilled it (it takes some time for oil filled in the valve cover to drip down and I guess I just didn't see it.

There was oil coming out the breather pipe -- maybe it interfered with the turbocharger's work?

[Bash]

Originally Posted by Dockhead

Update:

I changed the fine fuel filter and switched the dual Racors to the other side.

There was some debris in the fine fuel filter, but no water. How the debris got past the Racors, I don't know.

The oil was overfilled. I removed half a liter of oil to bring the level down.

Then I motored for more than an hour at 2800 RPM, which is above my usual cruise RPM of 2400 to 2500. The engine was performing completely normally.

Can it be that all this hassle is from an overfilled crankcase? I topped up the oil in Cherbourg before departing on the trip during which the problem occurred. I seem to have overfilled it (it takes some time for oil filled in the valve cover to drip down and I guess I just didn't see it.

There was oil coming out the breather pipe -- maybe it interfered with the turbocharger's work?

Interesting. My Yanmar manual (4JH3-TE) says not to motorsail beyond 17 degrees heel. Could we theorize that with the overfilled crankcase even less heel could have created trouble for the turbo? That seems like a logical possibility to me.

[Dockhead]

Originally Posted by Bash

Interesting. My Yanmar manual (4JH3-TE) says not to motorsail beyond 17 degrees heel. Could we theorize that with the overfilled crankcase even less heel could have created trouble for the turbo? That seems like a logical possibility to me.

That's exactly what I'm thinking.

Does anyone know whether oil out the breather pipe into the intake tract upstream of the turbocharger could cause these symptoms -- loss of power and revs?

[Philsboat]

Sometimes in heavy seas the pickup filter in the tank can be plugged by crap in the tank that is sloshing around.A quick fix for that is to pull the fuel line off and blow back to the tank to clear the pickup, tube then bleed the system.
If that solves it then clean the tank.I cleaned mine and there was 1/4" of black slime in the bottom of the tank

Phil

[SaltyMonkey]

So, you are telling me that your mechanics and yourself never check the oil level up to this point?

[zeehag]

exhaust elbow WILL give those symptoms--i know--btdt. so will fuel filter, btdt... gooodluck..i really hope is the fuel filter --but i have a feeling is the elbow...

[Dockhead]

Originally Posted by SaltyMonkey

So, you are telling me that your mechanics and yourself never check the oil level up to this point?

Fair question. It had been a bit down from the top mark on the dipstick, and in Cherbourg I topped it off. Naturally, I checked it then but I guess not all of the oil had come down out of the valve cover into the sump.

I checked it after we limped into port, and seeing that it was enough, didn't pay too much attention. Just today I checked it again and realized that it was quite high and decided to remove some oil.

[delmarrey]

Yanmar put a little yellow tag on my dipstick that says to check the oil 10 minutes after shutdown. I noticed any longer and it will read a bit higher.

[sabray]

Some times you'll hear wait 20 minutes after running to check oil.
Now I'm wondering is the oil to full because you added oil right after it ran or is something else in your oil that has raised the level? Oil analysts maybe.

[marc2012]

A bad fuel pump diaphram will leak diesel into oil.It will also affect performance.If those have one .marc