What to expect from your engine inspection

Story by Harris & Ellis / July 12, 2023

Author: Jeff Cole, Yacht Broker Harris & Ellis Yachts

Most buyers will invest in a yacht survey before purchasing a boat. Another option is to also engage a professional to inspect and test the engine(s). It’s an added cost but can save time and money down the road if it identifies serious engine issues. Even when there are few or no issues, you can come away with a helpful list of expected short- or long-term maintenance items on your new boat.

Engine inspections happen when the boat is in the water, at the dock or, preferably, as part of a sea trial. Your inspector will spend several hours on the boat for a simple small diesel, and up to a day for a boat with twin engines and a generator. Afterwards, you’ll receive a written report of findings, but you should also get a verbal briefing on the key points immediately following the inspection.

The first stage of the assessment is a visual inspection of the engine and supporting systems. The inspector will check the oil and coolant levels and assess their condition. Is the oil clean? Does the coolant look fresh? Are there any leaks of lubricants or coolant?

Some buyers ask for an independent laboratory analysis of the engine oil, but analysis can take up to two weeks, and ideally the report will be compared to prior reports to spot trends. Those are rarely available.

Auxiliary systems are checked to be sure that all belts are tight and properly seated and that there are no signs of wear or obvious belt dust. The inspector will also make sure hose clamps are free of rust, and that fuel, water, and exhaust hoses are clamped and secured against vibration. The starter and alternator wires should be properly protected and they, plus the motor mounts and shaft coupling or outdrive, should all be in good condition.

Now the engine can be started, and the inspector will make sure that the blower runs (important on both gas and diesel engines) and that the control generates appropriate alarms when the key is turned but before the engine starts.

The engine should crank well, starting easily and smoothly, though it may be fussy if it hasn’t been started in a while. Look for adequate cooling water flow from the exhaust at idle, and colourless exhaust gasses, at least after the engine warms up.

The inspector will also check that compression is relatively consistent across all the cylinders.

Even if you don’t have an inspector onboard, on the sea trial you and your broker can let the engine run for a while at about three-quarter throttle to warm up, and check for inboard exhaust leaks, proper cooling system operation, and smooth running. You can do a short run at wide-open throttle to evaluate exhaust smoke, smooth operation, and appropriate RPM to generate optimal power to the prop.

After shutdown, check the engine again for signs of oil or coolant leakage.

Categories: Buying a Yacht, Selling a Yacht