Before starting
- Look and smell for diesel, oil, coolant, seawater and exhaust leaks.
- Check bilge level and investigate any new fluid.
- Check engine oil using the specified procedure.
- Check coolant only when safe and cool.
- Confirm the raw-water seacock is open and strainer is clear.
- Check belts for damage, tension and contamination.
- Inspect hoses, clamps, wiring and mounts visually.
- Confirm fuel level, shut-off position and filter condition.
- Place the gearbox in neutral and test control movement.
- Remove loose tools, cloths and stored items from the machinery space.
During the first 60 seconds
Confirm oil-pressure and charging warnings clear as expected. Look over the stern for cooling-water discharge. Listen for belt squeal, exhaust change, knocking or grinding. Check the engine bay for active leaks without approaching rotating parts. If the raw-water system has been opened, confirm it has primed.
Underway
Warm the engine under moderate load rather than prolonged cold idling, following the manual. Periodically scan rpm, temperature, pressure and voltage. Check the wake and exhaust for smoke or steam. In a twin installation, compare engines at the same commanded load.
After shutdown
Look for leaks, belt dust, coolant odour and unusual heat. Record hours and defects. Close seacocks only if that is the boat’s established procedure, and use a clear control so nobody can start the engine with cooling water shut.