38' 1984 posillipo technema with Fiat Iveco diesel engines question

Fiat Iveco Aifo 8361-125-530

I have 270 hp iveco engines in my boat, both are emitting white smoke , the starboard engine is also giving a tapping sound, suspect valves need to be adjusted , but am not familiar with this engine to know if that is what it could be. Both engines run strong, start right up,.

new rebuilt fuel injectors
added anti bacterial to the diesel fuel, have added seafoam.

Replaced all fuel filters , oil change and serviced. motors seem to be in good shape , around 1200 hours .

the smoke appears cold or hot , doesnt seem to matter, less white smoke at lower rpm, but still present ,

took the boat from Huntington Harbor to Ventura Harbor and is running fine, I just want to make sure I am not damaging the engines with the tapping on the one engine and both emitting white smoke , not too heavy , but definitely present and continuous.

any input from a good diesel specialist or knowledgable expert would be welcome, mu mechanic seems to be out of ideas.

The input i have received from others when asked seems to point to water separator or water cooling too much in the heat exchanger or? beyond that I am lost :<

any help or recommendation for a good mechanic in the So Cal area would be appreciated !

 

If injection has already been addressed, your likely next culprit is probably turbo issues. Was the antibacterial additive done for a particular issue? Did you add the additives before or after the injector work?

 

Hello, appreciate the reply , but I guess I don’t follow how the turbos could generate the white smoke , on turbo was rebuilt about 5 years ago . The antibacterial was to check to see if fungus had polluted the diesel tanks , since I have had the boat , I have put about 100 hours on it , so I think I have run enough fuel through it ?

 

What is the engine temp? Should be slightly above 80 C (max 87 C). If too low, there will be white smoke. Some Iveco's have "oversize" oil coolers keeping engines too cold at low loadings. But if you have wet exhausts, white steam indicates lack of cooling water. Have the injection pumps been tampered with, fi injection timing?
Of course, check the valve settings on both engines; sometimes the sound from injectors can resemble a "tapping".

 

In general, too much fuel will give black smoke. Engine oil may be gray smoke. Either one can be detected by the smell. If it is steam, it could be overheating. However, in cold weather it is normal for the water vapor to condensate and make a white cloud behind the boat.

 

Hello and thank you for the very imformative input? the Portside engine is running around 80C and the Starboard side engine is running at 100c, ( the temp sensor is jumping around , so I need to check it for accuracy) engines both emit white smoke continuous from both sides. From what I have read, the timing of the fuel injection pump could be over feeding the engines . but i am having trouble finding a mechanic familiar with the Iveco 8631 , 8.1 diesel engines. rebuilt injectors did not change the smoke level at all. The valve settings will be next on my list and checking the water intake as well. Thank you for the direction!

 

If it's a common fuel tank then I would suspect water/fuel issue.
If they are separate fuel tank fed then I too am stumped.
Whatever it is, is common to both engines, this is a major clue.

 

Thanks for the insight , you make a great point that the major clue is both engines , I have replaced the fuel/water separators , etc.

 

To exclude fuel issues run one engine with fresh clean fuel without additives.

 

My early thought was off the cuff with not a lot of time for a full response. I was working under the assumption that you had already fixed injector issues, as well as ruled out any possibility it was white blue smoke from a heavy blown head gasket. I myself have chased my tail with injector issues only to discover turbo's where my issue and rebuilt turbo's solve the white smoke.

It could be intercooler leaks, turbo seal issues as well. Billowing consistent white is bad air fuel mixture. Options are poorly atomized injectors or turbos not producing enough air for the mix.

Suppose it could also be a timing issue, but most modern common rail engines rarely function well timed that far out across all power ratings.


In your shoes my honest hunch is to look back at fuel. It's possible both mains had similar age related intercooler or turbo issues but far more likely to have shared fuel source issues.

20c is not trivial engine temp difference but if its a gauge issue thats easily explained away.

My school of hard knocks boat repair education has taught me that often the easy fix solutions rarely fix anything. High pressure diesel injectors don't like injecting stuff that isn't diesel, this can include various fuel additives.

Back when I started out my skiff had some bacterial growth in its aluminum tank. Dumped a fresh set of filters in and some additive... and not much longer was capable of setting off a defense screen like it was the battle of jutland. Local old school mechanic informed me of my mis deeds and gave me a double racor pump setup. We drained the tank and put in new diesel that we flushed through a set of daisy chained racor filters. Then it was new injectors and a fuel pump worth of education.

All that to say, my hunch would be to re visit injectors and fuel pumps. If those test out OK, id move on to the air side of the equation.