An overheating boat engine is one of the biggest risks associated with the summer season. In this post we will discuss how you can maintain your boat engine during the summer, with tips on what you should do if your engine starts overheating.
What Causes Engine Overheating?
Boat engines can overheat at any time of the year, but overheating is more likely in the summer. This is because:
- Strain on the engine: You are more likely to use your boat for extended periods over the summer, and with shorter breaks between each use. Over time, this can put a strain on the engine and its components.
- High Temperatures: Higher temperatures in the summer months can mean that the engine’s cooling systems have to work harder, which can eventually make them less effective.
- Shallow waters: The specific waters in which you use your boat can also increase the risks of your engine overheating. Shallow waters, for example, can cause sediment to enter your engine’s cooling systems, which can affect their performance. Plus, if there is a lot of debris or vegetation about, it can clog your engine’s water intake, which can also affect the effectiveness of your cooling system.
- Saltwater: If you take your vessel out to sea, saltwater can, over time, block your engines cooling systems, which can eventually lead to overheating.
Understanding Your Engine And Cooling System
Getting to know your engine and cooling system is key to understanding and preventing overheating.
Outboard engines
These are water-cooled. The engine draws in water through an inlet before discharging it from the tell-tale. If the cooling system is operating, there should be a small stream of water emanating from the tell-tale while the engine is running.
Inboard engines and stern drive engines
Like cars and other road vehicles, these may rely on engine coolant, along with a heat exchanger that relies on a flow of raw water to keep cool. Or, they might be entirely water-cooled, via thru-hull fittings or a special strainer for saltwater.
Air-cooled engines
Certain smaller outboard engines are air-cooled, rather than water-cooled. The engines feature passages allowing for a flow of air. Excessive loads or blockages can place a strain on these systems.
How To Tell If Your Engine is Overheating
There are some obvious signs that your engine is overheating:
- Steam might start emanating from the engine compartment.
- A strong smell of burning.
- The engine may sound strained.
- Temperature gauge rising into the red.
Depending on the specific type of engine your boat uses, there might be other early warning signs that things are starting to overheat. If you have a water-cooled system, for instance, look out for a reduced flow from the system’s tell-tale. Some engines will display warning lights if the coolant engines are running too low. And most engines will experience performance issues if they get too hot.
What To Do If Your Engine Starts Overheating
- Turn off your engine immediately. Set the throttle to idle, and stop wherever it is safe to do so. The longer you run an overheating engine, the worse the damage will be, and the more the repairs will cost you.
- Give the engine at least 30 minutes to cool.
- Check the system for faults. Pay particular attention to the coolant levels, and top them up if need be. Also check for blockages wherever they may develop, such as in the outboard water intakes, the thru-hull fittings, or the air intakes.
- Aim to get your engine system fully inspected and, if necessary, fully serviced before you take to the water again. You should certainly get professional help if your engine will not start again after overheating, or if you notice any visible signs of damage to the cooling system.
How to Prevent Engine Overheating
Regular maintenance will help you prevent your engine overheating.
Read the manufacturer’s instructions for guidance on regular engine maintenance, and make sure you carry essential maintenance equipment, and spare parts as necessary. Regularly monitor your engine’s coolant levels, and keep an eye on the temperature gauges whenever you are running your boat.
Regular cleaning can also help prevent engine overheating, as it can prevent blockages from developing. For seagoing vessels, you should regularly flush your cooling system to remove any blockages caused by saltwater.
Be sure to read our full guide to mid-season boat checks and maintenance that will help keep your boat in full working order throughout the summer and beyond.
Get The Right Cover For Your Boat This Summer
Everard Insurance Brokers are the specialist marine trading division of accredited Lloyd’s brokers James Hallam Limited. We can help you ensure you have the insurance you need to cover your boat all year round.
Find out more about our dedicated marine insurance services.