People To Know Problem's Boat Engines

[Andrewcook]

As to Boating either Private or Hiring they have Various Gauge's such as Water Temperature / Oil Pressure and Amp Meter on the Dash Board to tells us if either of those gives rise of concern. Does any one know how to spot a problem if and when the Engine is Running Ruff Injectors? or the Tappets are Rattling or the Engine making a knocking Noise as Diesel  Engines are fairly noisy when running can any of theses problems be avoided? One other Question how long do Engine's last and what's the best one to have in Boats is it Pay to have the Cheap one that last longer or does the Expensive One last out longer?