Joined
·
39 Posts
- Reaction score
- 11
rockDAWG -
Black smoke in a diesel? Not an underload (propeller) problem.
If the prop fell off - no load, max governed rpm could be achieved, and boat would not move. Same with slipping or malfunctioning transmission.
If for some reason prop achieved more than maximum pitch, boat would seem much faster underway, until engine torque is insufficient to further increase prop rpms. (like starting out in too high a gear in a car) This would cause black smoke, but would be evident by a change in behavior underway.
Overfueling - start cheap - air filter condition? Is the engine getting air?
Next:
Is the soft piping for the turbo leaking - trace the hard piping to the hoses and look for sooty residue, indicating exhaust gas leaking. When the soft hoses fail, boost escapes, again causing on overfuel condition.
Or, more expensively, dirty/faulty turbo - injection is set to fuel engine with "boosted" air under pressure from turbo. If turbo is not feeding extra air, engine is overfueled (black smoke/cannot achieve governed rpm).
If engine is idled excessively, or operated under light load, then carbon buildup in turbo/intake/valvetrain is culprit.
Amount of oil consumption was not indicated, remember turbo has an oil line, if turbo stalls, intake vacuum could be pulling oil from turbo into intake, causing oil loss.
Good luck -
CHW
Black smoke in a diesel? Not an underload (propeller) problem.
If the prop fell off - no load, max governed rpm could be achieved, and boat would not move. Same with slipping or malfunctioning transmission.
If for some reason prop achieved more than maximum pitch, boat would seem much faster underway, until engine torque is insufficient to further increase prop rpms. (like starting out in too high a gear in a car) This would cause black smoke, but would be evident by a change in behavior underway.
Overfueling - start cheap - air filter condition? Is the engine getting air?
Next:
Is the soft piping for the turbo leaking - trace the hard piping to the hoses and look for sooty residue, indicating exhaust gas leaking. When the soft hoses fail, boost escapes, again causing on overfuel condition.
Or, more expensively, dirty/faulty turbo - injection is set to fuel engine with "boosted" air under pressure from turbo. If turbo is not feeding extra air, engine is overfueled (black smoke/cannot achieve governed rpm).
If engine is idled excessively, or operated under light load, then carbon buildup in turbo/intake/valvetrain is culprit.
Amount of oil consumption was not indicated, remember turbo has an oil line, if turbo stalls, intake vacuum could be pulling oil from turbo into intake, causing oil loss.
Good luck -
CHW