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Capt John

wrote:
I recently bought a used Volvo TAMD 31 engine for my 24' fishing boat.
This motor went through a major refurbishing job - the 4 pistons and
its cilinder vests (sp?) were replaced for new ones, new valves were
installed plus all new wiring, filters, etc were put in place, and the
motor went through a tuned up. After the motor was installed in the
boat, I let the motor run at low rpm for almost 100 hours before
putting the motor to its max. Just last week, the very first day after
this looooong break-in period, I let the boat go at full throthle for
about 30 minutes and everything seemed to go very smooth (nice steady
sound, no heavy smoke). After this 30 minutes passed, the engine choke
and went dead. Seems to me (as you can tell I do not have much
mechanical knowledge) the exhaust filter is giving off excessive
smoke, part of which is going to the turbo intake and choking the
engine due to the lack of oxigen. The mechanic suggested to replace the
exhaust hose to a different spot, which I don't agree because it does
not get rid of the original problem (excessive smoke). Any insight you
could give me will be greatly appreciate it!! I would be glad to
provide any details as you see fit.

Thanks!
Al

First, running an engine at full throttle for half an hour is really
not a good idea. What color was the smoke? Black smoke indicates a fuel
rich condition, blue smoke indicates engine oil is being burnt, and
heavy white smoke indicates unburned fuel (bad exhaust valve). A bad
seal in the turbo could be a problem, but if it's that bad the engine
will frequently "run away" (you can't shut it down and it keeps
speeding up until it consumes all the engine oil, at which time it's
life is over, sometimes in a big way). You might want to go to the site
"www.boatdiesel.com" and ask there. Their are some very good people
there, I'd give them a try.

John