Levin
I used to be a diesel mechanic in the army 15 years ago. The engines were a little different but I can tell you a few things that will help you realize yourself. Diesels don't have many of the problems that gas engines have so what can be discovered without extensive work isn't much and is easy to do.a) check belts for cracks...or just replace them anyway.b) replace fuel filters (usually more then one). May need to bleed the fuel system afterwards.c) get a multimeter and check the output volts from the alternator...should be at least 14.d) listen during startup and during running for any noises. Diesels run loud, but if there is a noise coming from inside the engine, then you will want to take an oil sample to a machine shop and have them run a test on it. They should be able to tell you what's wrong on the inside. Water pumps is a good place to listen for metal on metal sounds.e) look for water leaks while it runs, especially around the water pumps.f) replace your impeler.g) change your oil and oil filter.h) check your Transmition oil and engine oil after changing.i) check coolant levels.j) clean raw water filters...if you have a raw water engine.Most things on engines give warning signs before they go and these warning signs are usually some kind of sound. If your engine isn't making any unusual sounds then you should be fine. Some things though just don't give warnings and can't be noticed until it happens. If you don't know how to do any of the above things, look for a book about your engine and that should be enough. Worse case, make friends with somebody in the motor-pool. When I was in the army, all it took was a case of beer.As the other posters said...things don't break in the marina...and usually break at the worse times with the worse weather conditions so your going to have to learn how to do it yourself unless you got a couple grand to throw at a tow.