We have received this question from a reader recently: "I had to replace the raw water pumps on my engines. Both had failed at nearly the exact same time (1450 hrs) and after some research discovered that 1500 hrs usage is about the life of these pumps. I was wondering what the typical life of other things like the starter, alternator, injectors and fuel pump would be?"
We are not diesel engine specialists, but we have maintained and repaired our own engines in our various boats over the years and have dealt with most issues. These parts certainly have a life span, but the life can be prolonged with proper maintenance and care. Diesel engines are built to finer tolerances and are usually reliable, durable and will accept much more abuse than gasoline engines. If well maintained, it will deliver 8,000 hours to 10,000 hours before it needs a major overhaul. Problems with diesel engines are usually relatively simple and with a little regular preventative maintenance one can avoid the need for repairs at sea. Diesel engines require clean fuel, clean oil, fresh air, and a good supply of cooling water.
Merely taking care of these things will go a long way to eliminating potential problems. All diesel engines have good user manuals that explain how the engine operates and how to troubleshoot problems if need be. However, it does not hurt to do some classes with your local engine dealer to learn how to deal with some basic issues.
The general rule is; If the engine sounds good, can reach intended RPMs and does not smoke excessively, your engine is good to go. Regularly check fluids, don't use bad fuel, and run your engine at least every 5 days or lay it up properly for long-term storage to prevent problems. If you are planning an extended voyage, it is wise to stock up on fan belts, fuel filters and impellers. A good reference book on the subject is 'Marine Diesel Engines' by Nigel Calder. Below are some articles that may be helpful: