Wondering how to maintain your marine diesel engine as it ages? You’ve come to the right place.

Diesel engines boast impressive durability, efficiency and longevity, but as they get older, they require more care and attention to continue providing reliable service. Keep reading for useful advice about caring for and prolonging the life of an aging marine diesel engine.

How to Service and Maintain a Marine Diesel Engine

Emissions standards and other regulations tend to become more stringent over time — yet many aging marine engines are still able to perform within the letter of the law. Here are some of the fundamentals of marine diesel engine service and maintenance:

Perform Regular Visual Inspections

There are several telltale signs you can see from a visual inspection of your marine diesel engine. These include:

Frayed belts

Oil streaks on the engine

Discolored paint (usually signifies excess heat)

Check the Fuel Lines and Replace as Necessary

Take time to study the fuel lines. Aging fuel lines made from flexible materials tend to become brittle and must be replaced, or you risk leaks and even fires. Fuel injection lines made from steel can develop corrosion and begin leaking as well. Don’t put off getting your fuel line components replaced.

Receive Regular Marine Engine Surveys

Performing marine engine surveys at regular intervals is a good way to stay ahead of developing issues.

In addition to sea trials, compression testing and oil analysis, engine portions of the survey includes inductive testing of the ignition, thermal imaging of the engine, and in most cases, full computerized diagnostics of the engine and component performance.

Replace Fuel Filters Each Season

Most marine diesel engines have two fuel filters built in — a primary and a secondary filter. Some larger engines have two secondary filters. As your vessel gets on in years, it’s wise to replace these filters more regularly than the manufacturer specs recommend.

Check the Cooling System

Saltwater isn’t always kind to marine engine cooling systems. If there are cracks in the impeller, water won’t flow properly into and through the engine.

Use a Fuel Stabilizer

Marine vessels built before 1990 were not designed to accommodate modern, ethanol-heavy fuels. For this reason, aging marine diesel engines regularly exhibit poor performance and even failure when these types of fuels are used.

Part of maintaining a marine vessel includes using fuel stabilizers in aging engines. Experts also recommend avoiding fuel dryers and octane boosters, which may worsen the problem.