How to destroy a new $20K diesel

[jongleur]

You have had an exhaust leak into your boat?!?!
...enough to cause less pressure than to push
water out the water lift muffler?

I just can't bring myself to believe that is
the whole problem.

[Terra Nova]

Originally Posted by Zingaro69

...The installer came up with this work around...

I'd fire him immediately.

[weavis]

Here is hoping the problem is indeed solved. An expensive walk on the dark side.

Best wishes that it is as simple as this.

[chala]

Originally Posted by FlyingCloud1937

Also is the anti-siphon is plugged?
Lloyd

Originally Posted by Zingaro69

Yes Lloyd the tee feeds the dripless shaft seal.

Originally Posted by chala

found that the 20 cents seal had swollen

All yours.

[hpeer]

Zing,

I think I can visualize well enough how an exhaust/ water muffler is to operate.

I'm pretty sure yours is NOT a proper separator.

I don't see how that would have led to your problem, but maybe. I think I can see how it could lead to future problems.

If I may suggest....in addition to what you are doing, why not investigate the exhaust/water separator looking at how manufactured one work and consider replacing the YWith a proper separator. Assuming, of course, that what you're have is just a Y and not a separator.

In fact I am going to look at them for our cc.

One advantage of it, I think, is that it should provide a drain for any water in the exhaust line. So if water did get into the exhaust through the transom it would just drain out through the water drain.

And it then also limits the amount of water that can possibly back up to the exhaust to just that volume from the water lift to the separator.

This is how I THINK they are to work.

[DeepFrz]

Congratulations on getting the engine running again. Good luck in the future.

[jongleur]

Could that silver thing which is in pix # 2, 3
and especially #9 be the water injector? If
it is, could it be installed upside down?

If the silver thing comes off the exhaust manifold and
then turns 90 degrees up, why wouldn't
the water injected there flow back to the
engine? Shouldn't the dry exhaust be going
down at least a bit before water is injected?

...unless the case is that there is a short pipe
extension inside and the water is, in fact,
injected at the beginning of the hose and
not at the top as it looks like on the outside.

Pardon my skepticism.

[Jesse]

Is there a drain at the base of the waterlift muffler?. If not, putting one on the intake side of the muffler would give you the benefit of knowing how much raw water remains in the system after shutdown and eliminating it.

[Jesse]

If the 4" to 3"+1" Y was moved from the upward side of the goose neck to the downward side it should remove any possible effects of unequal water/exhaust flow at lower RPM when reduced exhaust velocity might not clear the water from the system.

[slowpoker]

Here is a theory that can be easily tested to see if this is the cause for all the salt encrustation inside your unfortunate engine:
Just as glass jars are 'vacuum sealed', where the lid is puckered down by placing the lid while the jar is hot and as it cools, the lid is pulled down with a natural vacuum, a similar thing is still happening to your engine. I'll explain.....
When your engine is shut down, it is hot, the exhaust manifold and pipe to the mixing elbow are red hot. As everything cools, it forms a natural vacuum sucking sea water through those 2 exhaust hoses, 'straws' , that are filled with the cooling water and a little water gets into the exhaust manifold each time the engine cools down.
Nah, it's not the metal gasket at the manifold that was leaking deadly carbon monoxide, smelly exhaust, smoke and soot as well as sea water because you would have smelled it, seen the smoke in the engine room and been able to see the trace of the salt water leak or rusty streaks down the side.
Don't let the engine get damaged again based on an assumption, try this easy test:
Remove those 2 hoses from the manifold when the engine is off and cool, slowly fill with water as if to fill the muffler and see how far up you can still hold the solid water level on each. Probably close to the level of the exhaust elbow because the exit at the exhaust on one of them is higher than the elbow, and that's fine, but it needs to drain quickly down into the muffler and then to have a sudden upward rise of the hose out of the muffler and have a vacuum breaker, a vent, atop that loop so that the hoses would never have solid water filling the inside of them as to not be able to suck any back out, not even from inside the muffler.
Some of that water you see inside the hose is being sucked into the exhaust manifold by the natural vacuum of the cooling engine and when cool, the salt is precipitated and cakes onto the insides of the exhaust box and adjacent #4 cylinder.
The open or closed valves on the engine do not open the exhaust manifold to the atmosphere, a leaking metal gasket at the elbow would allow that and break the natural vacuum but that's deadly.
This is only a suggestion, an easy test and a theory, but to be sure, do revise the hoses and the exhaust system to minimize any possibility of sitting, solid water being available so close to the exhaust. Make it impossible for the natural vacuum to bring sea water into the manifold, even if by increasing the capacity of the hoses with a larger diameter soon after the elbow and then reduce it again if you must before the muffler. The water level test will give you an idea.
We are all hoping that your engine if fixed and stays fixed. Better New Year to you.
Slowpoker.

[chala]

Originally Posted by slowpoker

The open or closed valves on the engine do not open the exhaust manifold to the atmosphere

Normally a crankcase is vented, an open exhaust valve will allow seawater to dribble into the crankcase. When the crankcase is full the seawater will drip out of the air inlet via an inlet valve or the vent pipe. Depending how the motor is run it is possible that the little amount of water that entered the engine does not stay on the top of the piston but dribble into the crankcase or evaporate allowing the motor to start easily without damaging itself. For a small amount of seawater in the crankcase the water will evaporate leaving the salt behind when the engine is run. Water dilution is common in engine.
I have noticed that your siphon break is on the side of the boat and not centred. When heeling and changing tack that part of the sea water that remain in one side of the U can slosh into the other side and so dribble past the mixing elbow on it’s way to the waterlift.

Originally Posted by Sailmonkey

I have seen several instances of the pss seals being plumbed to the incorrect side of the vented loop.

The lower above LWL the take off to the PSS is, the less seawater will remain to slosh in the piping.

That the salt left into the manifold is due to vacuum, the aspiration of the engine kicking back or any other reasons, finding the reason may give peace of mind.
Also taking into consideration the amount of accumulated salt and the spg of the seawater where you navigate you should be able to assess the amount of seawater involved.

[Zingaro69]

So I have spotty Internet here and been very busy the past few days. Sorry to be late in my replies.

The siphon break is on the aft bulkhead. It is about 8" to port of the centerline. Not much. Will that make much difference?

So when we got the diesel running again we removed the house from the top of the muffler. Water was being expelled but no exhaust at idle. Once we increased rpms we got a fountain of water and exhaust. When we looked at the manifold gasket we could see carbon marks where the exhaust was escaping. At idle the leak wouldn't allow enough back pressure to lift the water up and out. Once the rpms increased there was enough pressure to lift the slug of water and so the exhaust leak was minimized. Unable to lift the water it was able to back up to the manifold. Fortunately the engine almost never spent any time at idle so we didn't die.

That is the working theory at the moment. We are keeping a very close eye on it and will open the manifold after a short period of time to check if the problem is resolved. Currently an even andhealthy mix of water and exhaust are being expelled from both exhaust hoses even at idle. The anti siphon is working properly. No one doesn't want a re occurrence more than us. I appreciate all the advice and support. Another boat is flying in a mechanic from yanmar next week. I'll have him look things over again. AND WATCH THINGS CLOSELY

Sent from my SM-G900H using Cruisers Sailing Forum mobile app

[chala]

Originally Posted by Zingaro69

Having a new gasket fabricated tomorrow.

I do not know about Yanmar but for Perkins the exhaust gasket is not of the type that can be fabricated.
It is common practice when starting an engine to check if some water is coming out of the boat and rechecks after a short time to make sure that the water that did come off was not the water that was standing in the waterlift and after that to check the water flow regularly.
This can save some money.