White smoke and oily sheen on water from new rebuilt Yanmar 3JH2E

[Woody on "Hannah"]

Anyone, please !

My newly bebuilt Yanmar 3JH2E [I did the labor and sent out block, head and injector pump to professional shops] is belching white smoke and leaving an oily sheen on the water. Yikes.
As an overview I rebuilt her cause she was belching a bit of white smoke (and leaving an oily sheen on the water!) Was over 5000 hrs in S. Pacific/Alaska with much of that low load for eng driven refrig (1300 rpm's) and we didn't push her hard enough due to inexperience (usually at 1800 when motoring.) I've learned alot since.
So after reading Nigel Calder and a few others I got up the nerve to pull the engine and sent out the parts. I had the specialist overbore the cylinders and shave the block a few thous'. I put in new almost everything new: pistons, main bearings, new valves/guides, seats, injectors, seals, rebuilt all pumps, new Yanmar mounts, hoses, mixing elbow, on and on. $4000 worth of stuff. The fuel pump is new and the injector pump appears as new. Govenor not messed with.
I ran the rebuilt engine outside my shop for an hour and put a temp 5 foot exhaust in a bucket. Engine sounded great (like now) but lots of white smoke with exhaust. Even after getting her up to temp (appro175 F) thermomter opened on que and she still smoked. So, I accidently kicked the exhaust hoses out to the bucket and almost all of the smoke went away. Humm. Anyway, so, I figured I could claim victory and put the engine back in "Hannah" (Tayana 37.)
Well, the smoke is back in full force (load or no load) and the oily sheen is still on the water. I played with the timing a few degees slower and faster, tried new fuel oil (outa jerry can), tried letting her run for a few hours to really get her up to temp, readjusted the valves, retorqued the head and readjusted the valves again, and no luck.
The engine sounds great. Low vibration and no wierd sounds of pre/post igniton, pinging, etc. In fact a certified diesel large engine mechanic happend to walk by, saw the smoke (it really isn't that bad, but I do expect near-perfect I suppose) and declared that she sounded great.
So, botton-line: after $4000 cruising bucks I am only slightly better off because now I have less vibration and noise.
By the way, same water exhaust system with anti-sypion, etc. Could back-pressure cause this?

Ideas anyone ????????? thanks, Woody

[irwinsailor]

Send "never monday" a private message. He will know what is wrong.

[Woody on "Hannah"]

Thanks, I'll try that. Woody

[Alan Wheeler]

Mate! doesn't that just peeve you off. After all that hard work and thought of saving money, you just feel deflated. Well don't fret just yet, lets see if we can give you some ideas of direction to head in.

Firstly, back pressure will not cause a problem like this.
And, it isn't just steam by any chance and not smoke at all??

Secondly, you do say the smoke ain't to bad. Is it just a case of needing to run this in. It's a bit hard to judge your comments without seeing it. However, here are some comments to help you.

White smoke and oily sheen sounds like unburn't fuel. This would normaly be due to a cylinder not firing. A cylinder not firing would normaly be due to lack of compression. But you have also said that the engine is running sweet. So this is a little strange. But just incase a cylinder is not firing, follow this simple excersise to start with. Try cracking the nut on the injector pipe at each injector. Place a rag around the nut as you releave it to stop fule from squirting anywhere. This will drop the pressure at the injector enough to stop that cylinder from getting any fuel. If one cyclinder taken out of play makes the engine run ruff, then the cylinder has been firing OK. If no change is noticed, then the cylinder is not igniting the fuel for some reason.

If this is the case, then I suggest you get yourself a Leakdown tester. This will give you a better idea of what maybe happening inside, without pulling down the engine just yet. The leakdown tester will give you a result of engine cylinder compression. Don't try using a compression tester, it will tell you very little. It could be possible a ring set has not bedded in, or has been damaged or a valve is not seating correctly. The leakdown tester uses compressed air to give a positive pressure inside the cylinder. A guage registers how much air is leaking and you can listen for leaking air to get an idea from where the compression pressure is being lost. If a valve is not seating, then you will here air escaping in either intake or exhaust manifolds and if it is past rings, then it will leak into the sump.
Hope this helps and keep asking further if you need.

[GordMay]

Woody:
We have more than several members, all much more expert than I on diesel engines.
As Gunnar suggests, ‘Never Monday’ (Pat McCartin, of Inland Marine Diesel) may offer masterly advice, as might ‘pwederell’, and others. Alan Wheeler (Wheels) has already exceeded my meager abilities, in this post and others in the Marine Engine threads.
The Oily (fuel?) Sheen, combined /w White Smoke and Smooth Running, suggests unburnt fuel to me.
As Wheels suggests, you should be able to hear a sticky Valve, so failing that, I’d think Rings, or Faulty Fuel Supply (restricted supply to 1 cylinder, or too much) ...
Regards, and good luck,
Gord

[By Invitation]

Woody,

I had a similar problem years ago with an old Volvo engine. Turned out that the heat exchanger was bad. I don't know if this can cause the smoke problem you have but the oily sheen on the water was caused by the bad exchanger. I know you can easily have them pressure tested to see if they are sound.

Hope this helps a little. I would also recommend talking to Pat before doing anything.

[Woody on "Hannah"]

Thanks Mates for helping me sussing out the problem,

We treat our engine like a one of the family/shipmate (got us all over NZ, Hawaii /S.Pac. and Alaska) so I really appreciate the help.

Seems we are in concenus that the white is unburnt fuel. To that ends I will crack the seals on the injectors to see it one of them is goofing off and if so I know where to go from there. Leak test is next. Makes sense that it's not backpressure and I do know for sure that the heatexchanger is working properly (Raw water endcap cold and other end hot - I flushed it back to specs myself.)
I was expecting someone someone to blame timing? or too cold (-5 C) ?


Again, thanks. Woody

[Alan Wheeler]

Just to help a little more Woody. The white smoke, If it is deisel, means it has not ignited. If timing was the issue, you would still have ignited fuel or no engine running at all. Black smoke means the fuel has ignited, but has not burn't efficiently.
See if a cyclinder is not performing, and come back to us. I have some idea's of direction to take you on, but need more info before I can suggest a direction. And by all means, see if you can call Pat. He maybe able to ask questions and give answers imediately on the phone.

I treat my engine like on of the family as well; the red headed step child
Going back to Wheel's comment, have you smelled the smoke to determine that it is smoke, and not steam? Probably a silly question, but as the tech support guys say, start with is it plugged in, and go from there. Also, did you buy the gaskets as a sealed kit, or was the head gasket a seperate part? and if it was a sealed kit, was it suited for multiple models? Just throwing some less common possibilities out there in case all else fails. The series of diag tests that Wheels suggested, should narrow it down.

[Woody on "Hannah"]

Kai Nui,
Thanks for that but quite sure it's smoke not steam: easy to differenciate now that winter has set in. Gasket was indeed from Yanmar's rebuild kit but was same as original. I'm convinced it's unburnt fuel.
Tomorrow I should be able to get down to her to determine if she is missing full ignition in one cylinder. But if so, and she in fact is pretending to be a two banger, then I really am in for a treat when all three come on-line !
By the way, with this rebuild I even replaced all of the clutch and friction plates and flex-plate in the marine gear [KBW10E] - what a difference. No thunk, no rattling, just silky power from the big fixed three blade. All of that was necessary because we let her free-wheel coming across the Pacific the past few years - expensive mistake. Barring a shaft-brake (or vicegrips) I am still a little confused if fwd or rev is best when sailing only. I suspect forward in a wet disk friction (ATF bathed) clutch ? The manual is useless in this area. ideas?

standing by, Woody

[never monday]

Sorry about the abcence. We lost DSL and power during our ice storm on Wed. and just got it back this morning.

I agree on the unburt fuel, as long as the white smoke doesn't have a sweet smell to it. If so, it could be coolant.
How many hours on the engine since the reinstall? have thoes been idleing or running hard? in gear or out? Following Wheels train it might not be fully seated yet.

What has your break-in procedure been so far?

[irwinsailor]

The Doctor is in.

[Richhh]

Cylinder head bolts/studs -

---- did you install them dry OR did you apply a gasket cement to the threads? I've never rebuilt a 3JH but many similar engines require sealant on the cylinder head bolt/stud threads to prevent water passaging from the waterjacket side of the block, up along the bolts/studs .... then ultimately leaking through the head gaskets into the combustion chambers. Without the sealant on the threads, pressurized exhaust gases will enter the cooling loop on combustion chamber pressure and will suck water into the combustion chamber on the downstroke. I typically use 'aircraft grade' Permatex for such stud/bolt sealing (silicone caulk on smallblock GM engines).

The excess 'white' (steam) exhaust emission is 99% a water leak between the cooling-side and the combustion side. The other 0.5% is a cracked block that you didnt discover during rebuilding ..... you did "Magnaflux" the block for cracks didn't you? ... magnetic or dye penetrant doesnt matter. A cracked block will have the same symptoms. Lets hope that isnt the case because only about 10-15% of cracks can be 'fixed'. The other 0.5% would be a pin hole in an exhaust manifold; but, without the oily sheen.

You might want to run the fresh water circuit as a 'closed loop' as a 'test', pressure it (15 psi), run the engine and see if you dont have a quantity loss of water .... would tell pretty quick for 'which side' raw/fresh the water is getting 'sucked' into the engine. Then (OR) shut down, pressurize, let sit with applied water pressure and look for the 'leaker' by observing a flooded combustion chamber, etc. Simple speak - pressurize the fresh water side with about 20 psi and see where the water accumulates. If you run the freshwater side as a closed loop you can purchase tablets that dissolve in the water circuit and if exhuast gas is crossing over to the waterside - the dissolved tablets will 'fluoresce' when you shine 'black light' on the water ... the carbon monoxide / carbon dioxide in the water will bind with the chemicals in the 'tablets' and will glow under black light .... NAPA sells such tablets.

I'd check with Mack Boring Inc. www.mackboring.com/ (eastern USA master distributor of Yanmar) to see if the head bolts/studs threads need sealing. Many automobile and truck engines need sealing of the head bolts or studs ... or you can get the same type of problem. Sometimes you can seal the bolts/studs by using a anti-leak compound mixed in the freshwater side (Bars-Leak, etc.) but that is only a 'band-aid' approach.

What was the price for a total gasket/seal set to rebuild? As Im just about to rebuild a 3QM30.

hope this helps

Woody, since you have determined that it is not steam, but smoke, the next question would be, did you replace the injectors when to did the rebuild? Also, have you smelled the oil that is being discharged, does it smell of diesel? Finally, when the machinist bored the cylinders, did he have the new pistons and rings? Again, these may sound like basic no brainers, but that is usually how such issues are solved. A bad injector can overfuel the cylinder and cause a cold burn, exhausting unburnt fuel. Just for kicks, can you post a picture of the smoke on the site? It might not be that abnormal for this engine.

[Alan Wheeler]

Yes, woody stated in his first post that it was new injectors, Pistons etc etc.
It's easy to get side tracked at this comment, but I am kinda confused by Woody's comment about "kicking the exhaust and the smoke went away" part. That has me puzzled.