Fresh Water System; Raw Water System - Camano 31 Owner's Handbook Manual

You can usually determine from which by the type of coolant in the bilge. If all else fails, a taste test
will tell you if it is antifreeze or raw water. Possible causes:
?
Closed sea cock
?
Coolant level low
?
Oil level low
?
Defective raw water impeller
?
Defective engine coolant pump
?
Plugged raw water filter
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Defective thermostat
?
Blown head gasket
?
Engine overload
?
Faulty temperature sensor

Fresh Water System

Check to make sure that you have a sufficient amount of coolant in the engine. Each Volvo engine has
a coolant expansion chamber and you should be able to see some coolant in the bottom of the plastic
expansion tank. If the coolant is down enough to cause the engine to overheat it probably means that
you have a leak somewhere and you should check this out. It is possible that the leak is slow and could
have been going on for some time before the level dropped to the point where the overheating alarm
was activated. Indeed, there may be no sign of coolant in the bilge if the leak was small enough that the
coolant was being evaporated by a hot engine before it could drip into the bilge. In the case of a very
slow leak, you can probably top up the coolant and return to port without difficulty.
Useful Tip: If the leak is not major you might want to consider adding a coolant sealer to the fresh
water cooling system. This will often keep things dry for a long time but you should keep a close watch
on the trouble spot. Have proper repairs done if further leaks show up.
If fresh water coolant has collected under the engine it could be because of a significant leak and you
should carefully check the engine where parts are joined by a gasket or an '0' ring, as well as the engine
water pump and all associated hoses.

Raw Water System

Salt water (fresh water on rivers and lakes) is brought to the engine through a hole in the bottom of the
boat. On some Camanos, that seawater intake is protected by a basic strainer. There is a pump at the
forward end of the engine which pushes the water through a more elaborate raw water strainer, several
heat exchangers (engine oil cooler, transmission oil cooler, turbo air after cooler, the engine water
cooler, and turbo water jacket) and then on to the water lift muffler. The engine exhaust then pushes
the raw water through the exhaust pipe and back to the sea. If there is raw water in the bilge, follow all
of the hoses from the thru-hull all the way to the water lift muffler for possible leaks.
Overheating can be caused by a blockage at the raw water intake (seaweed or a plastic bag etc.), a
failed impeller, a failed pump, or a blockage of the sea strainer. Checking the sea strainer is easy. So is
checking the impeller. Take off the impeller cover plate (being very careful not to damage the fragile
paper gasket) and make sure the rubber impeller isn't broken or torn. If it is, replace the impeller. That's
why you carry a spare. If the sea strainer and impeller are fine, then you might want to check the raw
water intake. Check to see if you can close the ball valve. If you can't then the odds are you have
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