Visit our Popular Forums

hooligan6a · 06-02-2011, 10:32

Yes, I have run it at the dock with a hot engine, still no smoke. As I have said at least three times, it only smokes underway. The impeller and mixing elbow would point to overheating. I does not overheat. There is plenty of water coming out of the exhaust. I am dealing with smoke not steam. It looks like smoke, acts like smoke and smells like smoke. it is not steam. There is no water in the fuel I have checked that, I have also changed all filters, half dozen times and changed the oil twice. I don't see that it can be any thing but the injector pump or the injectors.

Mundinho · 06-02-2011, 10:34

White smoke with engine under load is typically caused by not enough fuel compared to the amount of air available for combustion. Too much fuel (compared to air available in combustion chamber) will cause black smoke (not complete combustion of all fuel in that case). In your case the engine while reving up along side the key (zero speed) will be higher loaded then while steaming at same RPM (propellor formula). Hence at keyside your engine is pumping in more fuel to reach the same RPM as compared to while underway. If the engine is not super charged (turbo) the ammount of air has remained the same for the same RPM as while underway, hence the fuel / air ratio has changed in the sense there is now more fuel available alongside the key then while underway, causing complete combustion which is colorless.

You mentioned a reduction of power, this supports the above.

Typically this is caused by reduced volumetric efficiency of fuel pump (high pressure pump). This happens over time and is normal wear and tear.

A failing injector typically will inject more then required fuel in the cylinder (worn out injector spring or worn injector holes) which will cause incomplete combustion, which will become evident in black smoke from the exhaust.

The much cooling water (e.g. failing theremostat) again will typically result in not complete combustion (temperature not high enough in cylinder under load), evident in black smoke from the exhaust. Not enough cooling water will typically not result in a change in exhaust gas color, as the combustion is only improved with higher temperatures. Your engine material and engine structural limitations however require a limit to exhaust gas combustion chamber temperature, hence the thermostat requirement. Any issue with cooling water you should observe in your cooling water temperature (should be between 80 and 90C)

Your best bet is your high pressure fuel pump. There is not much you can do yourself typically. Pump pressure would be required to be measured to verify if these are still within the required range. Overhaul of bore and plunjers and valves will be required if worn out.

Best Peter A S

hooligan6a · 06-02-2011, 10:54

Peter, You told me what I did not want to hear but I think you are right. The engine is not that old so I don't think the pump is wornout, I think I got some dirty fuel. Do you think I should pull the injectors first? could there be some outside chance it be a bad one

captain58sailin · 06-02-2011, 11:05

It wouldn't hurt to perform a pop test on the injectors, perhaps there is one that is over delivering fuel, or dribbling. That would be your least expensive fix. If you don't find a bad injector, then look at the pump.

marc2012 · 06-02-2011, 23:00

Don't look back while running.marc

hooligan6a · 06-02-2011, 23:08

Marc, If I owned a Seawind II that's what I would do but I happen to own a very good boat.

**Dockhead** · 07-02-2011, 02:00

For what it's worth, my Yanmar (4JH3HTE) smokes like a chimney. When I bought the boat a couple of years ago, I insisted that the seller fix it. At that time the engine only had 830 hours on it and ran perfectly, but smoked. He had the injector pump overhauled, had the turbocharger overhauled, had the injectors ultrasonically cleaned -- all to no avail. I finally felt sorry for him and asked him to stop. My surveyor -- a specialist in motor yachts and a very good diesel engine guy -- could not figure out the problem either, and pronounced the engine sound -- "just a smoky Yanmar".

Since then I've put 250 hours on the engine and nothing has changed. White smoke in billows while cold, somewhat less after it warms up. Power and fuel consumption normal.

So maybe in your case -- "just a smoky Yanmar"? I will eventually replace the injectors and see if that helps, but it's already not high on my list of priorities.

hooligan6a · 07-02-2011, 04:24

I am on my way down to Panama to go through the canal. That is the one place you don't want to have a problem with your engine. For what they would charge for a tow I can probably replace my engine.

**Dockhead** · 07-02-2011, 05:20

Quote:

Originally Posted by hooligan6a

I am on my way down to Panama to go through the canal. That is the one place you don't want to have a problem with your engine. For what they would charge for a tow I can probably replace my engine.

I hope you have better luck than I did in diagnosing your smoking problem! Be sure and post about what you find.

hooligan6a · 07-02-2011, 12:09

I was told by someone to checck the tempiture of all 3 cylenders So I ran the engine and found that, the #3 cylender is running 20/25 degrees cooler then #1&2 what does this tell me? I don't have a clue.