Yanmar Smoking and Making Oil

[Gene :^)]

Looking back, I think Um Saudade nailed it back on post #12.

This also fits with my idea that the turbo may have been marginal before.

Or, this might fit that the prop has always been too much. Overworking the turbo for years and bringing us to where we are.

[Inthewind]

Check that prop for trash before throwing more wads of cash at your problem.

[um saudade]

Another dumb question:
Is it up to operating temperature? I still think turbo also but if the engine were running cold it would exacerbate all of the symptoms. Is it raw water or coolant system?
Um_Saudade

[Gene :^)]

I still go with the Turbo.

Without the boost, the cylinders are not receiving enough air charge to burn all the fuel and make the power to increase rpm. Running rich, blowing smoke and soot.

Engine RPM does not make the boost, Boost makes the power to make the engine RPM.
Engine RPM does not make the turbo spin, engine Load makes the turbo spin.

We have plenty of engine load, and plenty of fuel, but not enough turbo spin (boost) to provide sufficient air charge to burn all that fuel. Which means, not enough power to increase engine RPM.

Turbo bearings are not like the normally seen bearings with rolling bits. Turbo bearings are floating in a thin film of pressurized oil and are very sensitive to contamination or distortion.

[Boracay]

If you don't have the manual for your engine Yanmar have them on line here.

[delmarrey]

Originally Posted by sww914

I am not a diesel mechanic, I've never turned a screw on a diesel. I'm a Porsche mechanic. I'd like to work on diesels but I haven't yet.
The names of the parts are the same and that's about it. Gas engines with a lot of gas in the crankcase, especially if it ran into the crankcase through the cylinders (via leaky injectors for instance), will wash the cylinders of lubrication and ruin the rings. Does this happen on a diesel?

NO! Diesel fuel actually has lubricious added to it. The cylinders should never dry out. That's why one should NEVER use starting fluid in a diesel. If the rings are bad the the crankcase gets diesel fuel in it (leaking injectors) raising the level on the dip stick and can actually run away if the oil level gets to high.

[forsailbyowner]

No way to test turbo on bench? Would think there should be a procedure other than just trying a new one. I'd read the shop manual to find clearances, endplay, visual inspection points etc instead of just throwing money at it

[loowigi]

Hi Terri

Definitely do not think your engine is poked! If it is black smoke it is a fuel issue or lack of air in other words running rich. If it were blue smoke its burning oil which is not good. Have you checked there is nothing around your prop I know its a long shot but you never know. Blocked air filter. Have you removed the air filter and run it. You can here the turbo spinning, just don't skick your hand over INTAKE.

Good Luck.

[Tellie]

Originally Posted by Tspringer

It does appear that the engine is no longer making oil, though this is hard to prove definitively because we only have about 45 minutes of total run time since the oil was changed and it got new injectors and the new lift pump.

The boat was hauled out last month and the bottom is spotless plus all the other running gear was cleaned. Its not a fouled bottom.

So.... we have new injectors (the nozzles were replaced with new), a new lift pump, new oil and filters and clean fuel, we have a turbo that spools up and spins freely, we have no blockage in the air intake or in the after cooler, the run temps and oil pressure are good. We removed the breather line while running and there is no sign of any blow-by. In addition the engine starts immediatly now, on the first turn.

She does idle better now and in general seems to run smoother since replacing the injectors.. but the black smoke remains.

We removed the valve cover and turned the engine over slowly, she definitely has compression and there are no hissing noises or anything to indicate any compression issue or valve guide issues.

Water spits from the exhaust normally and she does not run hot.


At this point the techs here want to haul the boat and try a different prop. They and the regional Yanmar rep at Mastry insist that the problem must be the prop with the Max Prop over-pitched and thus overloading the engine.

This prop has been on this boat for 10 years. I have personally seen 3400 rpm with this prop (we cannot get over 2950 at full throttle right now) and the problem with the engine making black smoke even at 2400rpm cruise so bad that it soots up the entire transom is definitely new. How can the prop be the problem when the problem is NEW? The Mastry rep says the prop has been wrong all along and overloading the engine but now things have degraded to the point where it is manifesting itself in this way.

So.... the Yanmar folks, unable to come up with any other solutions, are blaming the prop. It looks like we will be here even long and will be getting hauled out yet again and trying a different prop.

I am at a complete loss.



Terry

I'm sure it has to be frustrating. A problem like this can't be diagnosed over the Internet. To many variables from what you have described. The rest is just guessing. So I'll throw in some guesses as well. First I'd go back to everything I disassembled and check them again. Second, I don't believe a mechanic said the compression is good because he turned the engine over by hand and heard no hissing and felt resistance at TDC. A compression test is the only way to properly figure out what the compression really is and the allowable difference between the cylinders. Third, you stated the injectors were rebuilt. Though the engine runs better at idle I'd want to know that the re-built injectors where properly tested before installation. It wouldn't be the first time that new nozzles were installed and assumed all would be fine. A pop test can determine the correct pressure and spray pattern. Did they give you these results?
Fourth, the turbo, tricky bastards they are. Others may disagree but personally hate them especially on long range cruisers. When they work they're great, when they don't it's an expensive part for a few extra HP. Another poster asked if you checked the side play, I would assume and hope the mechanics did. Fifth, I assume again the valve lash has been checked, twice. Sixth, in my humble opinion, if you were getting max 3400 rpm with the existing prop before, changing props now is a crap shoot by people that are at a loss to figure out what the real issue is. Losing 450 rpms seems very unlikely the fault of the same existing clean prop. Not all mechanics know everything, sometimes it takes a new mechanic with a fresh outlook. It might be worth taking advantage of Chief Engineers new service.

[Tspringer]

The injectors were pop tested before and after being rebuilt. Spending money on another set of new injectors seems pointless.

The engine starts immediately when turning the key when cold. How is that possible if it has compression bad enough to cause large amounts of black smoke?

As I said, the engine has been run with NO air cleaner and the problem is the same so its unlikely a blockage in the air cleaner. We have also searched elsewhere but cannot find any blockages in the turbo plumbing or in the exhaust. Water spits out the exhaust as normal and the temps are normal.

Next step is paying a diver to come look at the prop and see if it has something on it or if its not actuating fully.

If the diver finds nothing..... then I have to consider calling off our cruise, moving back home to find a job, finding the money somehow for a repower before selling the boat. Throwing thousands and thousands of dollars at this engine when nobody can tell what is wrong and nothing fixes is stupid. Soon I could have as much into it as a repower and still have a bad engine. This is a fiasco.


What new service by Chief engineer?



Terry

[delmarrey]

Originally Posted by Tspringer

Next step is paying a diver to come look at the prop and see if it has something on it or if its not actuating fully.

Terry

First try putting the gearbox in neutral and turning the prop shaft from inside the boat. And, can you see your prop from the dock side?

Some times the rubber in a cutlass bearing balls up and causes resistance or sea life works it's way in, but it should turn fairly free by hand.

[Tspringer]

We are going to haul again and check/reset correct pitch on the max prop and if that does not cure it next will be to rebuild the injection pump and after that a new turbo and then a full rebuild.....or repower. That appears to be the plan.

We will test the shaft rotation, cannot see the prop from dock.

Terry

[ViribusUnitis]

I'm not a pro diesel mechenic, nor did I sleep at a holiday inn last night, but I feel the need to throw my 2 cents in. I do work on automotive diesels, which as everyone says "they're not the same."

There is no way that the problem is the prop. The problem is the guy on the end of the wrench. I garrantee it. He doesn't know what the problem is so the's trowing a hail marry. And costing you a freeking fortune in the process.

You need a diffrent mechenic. If it's costing you this much, and you seem to be going no where with it, GET a diffrent mechenic. Maybe just a freash set of eyes will solve the problem. If anything, they can't be worse than your current one.

Even if it was overproped, you ought to be making loughts of boost at those rpms. The lack of boost is resulting in a lack of hp, and all the smoke. As far as what might be wrong, I'd guess the there is a blockage somewhere in the exauste plumbing. I would be extra careful to pay attention to the plumbing between the turbo and the anti-siphen valve, and the anti siphen valve itself. I would also check up to the point that the cooling water is injected into the exauste system. The problem is probably not after the water in injected, as you would probably see a great reduction in the volume of water comeing out.

If the valve sticks closed, or if you get a insect nest or rag, up in that plumbing, it would cause a sever lack of power, gobs of smoke, for no disernable reason. One some boats it's REALLY a pain to inspect. Expecally the valve, and the plumbing right after the valve.

The other item I would check would be the injector pump timing. Your mechenic seems to be a boob if he didn't catch the pick up pump problem, so double checking his work seems important to me.

[Tellie]

Originally Posted by Tspringer

The injectors were pop tested before and after being rebuilt. Spending money on another set of new injectors seems pointless.

The engine starts immediately when turning the key when cold. How is that possible if it has compression bad enough to cause large amounts of black smoke?

As I said, the engine has been run with NO air cleaner and the problem is the same so its unlikely a blockage in the air cleaner. We have also searched elsewhere but cannot find any blockages in the turbo plumbing or in the exhaust. Water spits out the exhaust as normal and the temps are normal.

Next step is paying a diver to come look at the prop and see if it has something on it or if its not actuating fully.

If the diver finds nothing..... then I have to consider calling off our cruise, moving back home to find a job, finding the money somehow for a repower before selling the boat. Throwing thousands and thousands of dollars at this engine when nobody can tell what is wrong and nothing fixes is stupid. Soon I could have as much into it as a repower and still have a bad engine. This is a fiasco.


What new service by Chief engineer?



Terry

I don't want to speak for him, but Chief has a new consulting type buisness for people that find themselves in your type of situation. Give him a shout I'm sure he will be more than happy to explain what he can do for you. I can hear the pain in your post Terry. Viribus is echoing the same thing I said before. It might be time for a new mechanic before you start throwing good money after bad. Give Chief a shout.

[Tspringer]

Diver found nothing wrong with the prop, it rotates and changes pitch as it should and there are no obstructions of any sort.

I am at Marine Consulting Services in Jacksonville, a Yanmar dealer with multiple guys who claim 30+ years of diesel experience. Not that that means anything at this point.

I may get into the diesel mechanic racket myself, it seems to be much like being a weather man. You know little, but have lots of theories and general philosophies. You play with lots of neat gear and tools but are still basically throwing darts. The pay is good, and nobody really expects you to bat more than 50% anyhow and when your flat out wrong you still get paid.

Sounds almost as good as a Government job!

If I stay here next is apparently to get hauled out to change the prop pitch. They are guessing at this point that since the boat probably weighs a bit more with all our cruising gear aboard that it has crossed that magic line where the wrong prop pitch for the past 10 years is now causing this problem. In other words, the prop has been overpitched but before the issue was not so critical but now it is.

Throwing more money darts in the dark is what it is. These guys have no idea what is wrong.... but then again neither does anyone else really. Going to another tech would seem prudent but the chances are equal that the next guy could be worse rather than better and besides he will also be a weather man.

Any idea how to contact Chief? Maybe paying 2 weathermen is better than one?!?!?!



Terry