Engine rattling & white smoke

[JCDuffy56]

Near end of five day cruise in LI sound, Block Island and up Narragansett, mostly motor sailing at 2500 RPMS, engine suddenly began a loud rattling, emitting white smoke. Sounded frankly like a rod was about to blow. Dropped RPM to 2000, all returned to normal, as if it never happened. Except it did when I returned to 2500 about 20 min later, though ran fine for about an hour. Third try, same result. Engine ran smoothly, no smoke at 2000.

700 hours. Yammer 3 cylinder on 1996 Beneteau Oceanis 321. Will talk to mechanic at Brewers Wickford RI on Monday. What's going on?

Thanks all

 

[centerline]

with what little info we have to go on, I would be looking for an injector problem, but it could also be a faulty fuel pump.... hope for an injector issue

 

[John Nantz]

Hit a rough patch?

Disclaimer: I'm not an engine guru but before hiring a mechanic one thing I'd go looking for is some kind of an air leak in the fuel line.

For example, just thinking about your trip and the engine performance issue, given that the boat is a '93 and you were on the outside, did you go though a bumpy "rough patch" that could have stirred up the fuel in the tank? If so, perhaps air or crud or air bubbles could have made it into the fuel line.

Check the tightness of all the fittings to make sure they're up to snuff. Bleed the lines at the injectors. After the boat has settled for a day if the problem doesn't reoccur then maybe it was air in the line from fuel sloshing around in the tank.

Diesels like fuel and air, but both in their proper places.

 

[Benny17441]

Sounds like fuel starvation. First replace your filters both for the water separator and the secondary. Sometimes when you take a boat out into bumpy conditions sediments in the bottom of the tank get stirred up and can quickly clog a filter. If that does not cure the problem then move on to other possibilities. Always carry spare filters and learn how to replace them underway.

 

[JCDuffy56]

Update and still working it. In reverse order....
Fuel injectors next
Fuel polishing
Fuel filters.


Fuel filters were a mess. Secondary had not been changed for season, or prior season for that matter. Boatyard should have done so on spring commissioning

So out in trip, engine stalls, and will not restart. Looked closely into fuel, and, yeah, needed fuel polishing. "Worst I've seen this year", says the fuel guys. Green neon colors prompts a wondering question. "Never seen that before. Maybe someone put glycol antifreeze down there?", he asks.

Next up, rattling and white smoke recur after fuel polishing and ensuring filters are clear.

Now next up, fuel injectors. I trust this will be final. Will update.