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RickQuann 07-18-2008 01:09 PM

Diagnose your diesel engine
Received this in an email and thought that I would share it

Hints from Admiralty Yacht Sales -- Diagnose your diesel engine
While this is not intended to be an exhaustive list of methods to diagnose your diesel engine's general health, there are several non-technical techniques to check the health of your engine. Make sure your engine is warmed up before diagnosis.
Diagnose your diesel engine's running condition by the color of its exhaust:
Black smoke - Indicates unburned fuel/highly loaded condition
  • In situations where the boat has reached hull speed and the engine has enough power to try to make it go faster, black smoke will result. Back off the throttle a few hundred RPM's until the black smoke disappears or reduces to gray smoke.
Black smoke with oil sheen and soot on the water
  • May indicate plugged, worn or dirty injectors. Running the engine hard for 15 minutes or so may clean up the exhaust. If after this "blowing out" period the black smoke continues, injector service may be necessary.
Gray smoke
  • Indicates normal running condition. All diesels produce some level of gray smoke and may leave a sooty film on the transom of the boat. If a great deal of soot is present, see "black smoke".
White smoke
  • Probably indicates steam. Check engine temperature and volume of exhaust water to insure the engine is running at the proper temperature. In cold weather, white smoke is normal when engine is at operating temp.

funsailthekeys 07-18-2008 02:02 PM

black soot in the water
I had this problem with a generator. The genset seemed to run just fine except that it looked like a tire fire in back of the boat and the water had an black soot over it. After two generator companies came out and checked the injectors and everything else you can think of they said we needed a new genset, this one was just wore out.(1750 hrs) After puting the thing back together again (2ND time) I just happened to check the air filter screen and it was completly closed with exhaust soot! So I cleaned the filter assembly and it was perfect! No smoke, no soot , just clean water out the exhaust. I guess you don't always get what you pay for. These guys weren't cheap. So I learned something new.The companies you hire don't always know more than you and make sure the filter screen is clean.:)

trantor12020 07-18-2008 06:58 PM

hello funsailthekeys, I do think the genset company knows more than we think they know. its their business. what probably happen is this: send a service engineer and he sell spare parts, send a sales engineer there and he sells a whole new genset. so I guess it make prefect cents to send a sales engineer. ;)

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