What Is Included in a Pre-Purchase Engine Inspection?

An engine check may be visual and dockside, or it may include compression, electronic scan data, oil sampling, and a sea trial when appropriate and authorized. Access, engine temperature, seller permission, and haul-out status affect what can be tested.

The inspector should verify model and serial information, look for leaks and corrosion, inspect fluids and service items, observe cold starting where possible, monitor charging and cooling behavior, and note abnormal smoke, sound, vibration, or control operation.

An inspection describes accessible condition on that day; it cannot guarantee remaining life or reveal every hidden defect. A qualified marine surveyor should evaluate the hull, structure, safety systems, and broader vessel. Written findings help the buyer decide whether to proceed, negotiate, or request deeper testing.

Request access to a genuinely cold engine when cold-start behavior is part of the scope, and arrange permission for scan tools, fluid sampling, compression testing, or a sea trial before the appointment. Make service records, keys, battery power, fuel, and cooling water available.

If a seller declines a test or access prevents inspection, the written report should say so. Buyers can then treat the missing information as uncertainty rather than assuming an untested component is sound. Coordinate the engine inspection with the survey and haul-out so findings can inform one another.