Engine Symptons and Diagnosis
Below are a few symptons and suspected diagnosis. These are merely based on often seen problems and may have underlying causes that require closer inspections.
- Black smoke under load
Dirty air cleaner, turbocharger problems, overload, overfueling — Mostly fuel related problems
We recommend changing air filters regularly, cleaning AirSeps annually (if installed) - White smoke
Leaking head gasket, cracked head, block or line, bad injector(s)— Could be water related problems - Unusual noise
Bearings, wrist pins, turbocharger or injectors — Hard to self-diagnose
This will require a sea trial with someone to navigate the boat, while the mechanic inspects the engines. The problem may not be engine related at all, it could be drive train related. - Lack of power
Dirty air cleaner, dirty fuel filter, governor out of adjustment, injectors malfunctioning, bad fuel
Regularly changing air filters and fuel filters will eliminate the most common problems. This could also be a dirty bottom or propellor. - High oil consumption
Worn rings or liners, worn valve guides, worn bearings, worn turbocharger seals
This type of problem should be rectified as soon as possible before leading to more serious engine problems. - Increased fuel consumption
Leak in fuel system, dirty air cleaners, poor operation
Installation of Floscan monitorto moniter fuel usage is recommended. A barnacled bottom or propeller could also cause increased fuel consumption. - Increased oil level
Coolant leak, accidental overfilling
Filling oil when engines are cold will cause overfill when oil heats and expands. If water is present the oil will be obviously off color. - Overheating
Cooling system problems, worn belts, plugged hoses, low coolant level, damaged or malfunctioning temperature regulator
Any salt water system should be periodically flushed, especially heat exchanger due to build up of salt in the system which causes diminished water flow and higher temperatures. - Hard starting
Worn injector pump, low cranking speed, poor quality fuel, plugged fuel line or filter, battery problems
Usually determined by the sound the engine makes when trying to start among other clues. - Debris in the oil filter
Excessive bearing wear, damaged internal parts, coolant or fuel leaks into the crankcase, extended oil drain interval, improper oil, additives
We recommend an oil analysis on a regular basissymptomsh symptons early enough to correct before they lead to more serious problems.
Oxford Yacht Agency
317 S. Morris St
Oxford, MD 21654
410-226-5454
sales@oya.com