Cooling System - Volvo Penta 22 Series Instruction Book

Cooling system

The cooling system is divided into a freshwater and a seawater system. The seawater pump sucks water into
the seawater system through the drive/reverse gear. The seawater is then pumped through the charge air
cooler (CAC) (TAMD22), heat exchanger and the oil cooler (not MD22L), and then into the exhaust elbow pipe
where it is mixed with the exhaust gases. The freshwater system is the engines internal cooling system. It is a
closed system driven by a circulation pump. When the thermostat opens (at operating temperature) the
freshwater system coolant flows through the heat exchanger, where it is cooled by the seawater.
WARNING! There is a risk of water penetration when working with the seawater system ( if the boat is in
the water). If a plug, pipe or similar below the waterline is removed water can flow in. Therefore always
close the seacock. If the boat does not have a seacock (boats with SX-drive for example) the water
intake must be completely blocked, if this is not possible the boat must be taken out of the water before
work begins.
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Coolant. General
The freshwater system must be filled with a coolant
that protects the engine against internal corrosion and
from freezing, if the climate requires it.
IMPORTANT! Never use water alone.
If the freshwater system is filled with an anti-corrosion
agent mixture it must be changed every year. If the
freshwater system is filled with an antifreeze (glycol)
mixture it must be changed every other year.
We recommend that a mixture of water and Volvo
Penta antifreeze is used all year round, regardless
of the climate.
Water quality
To avoid the risk of blocking the cooling system the
coolant should be mixed with clean water. If there is
any doubt over the water quality distilled water or
premixed coolant should be used.
In event of frost risk
Use a mixture of Volvo Penta antifreeze and pure
water (the mixing ratio is on the packaging). Mix the
coolant in a separate container before filling.
IMPORTANT! Always mix so that full anti-
corrosion protection is retained.
WARNING! Glycol is harmful to health
(dangerous if ingested).