Checking Coolant Level; Flushing Cooling System - Sea-Water Section; Testing Coolant For Alkalinity - PCM HO303 MPI Owner's Operation And Maintenance Manual

ENGINE MAINTENANCE - 11

CHECKING COOLANT LEVEL

WARNING
Do not remove cooling system fi ller cap when the
engine is hot. Allow the engine to cool and then
remove the pressure cap slowly, allowing the
pressure to vent. Hot coolant, under pressure, may
discharge violently and cause severe burns.
Degas Bottle
The "see-through" degas bottle is connected to the
heat exchanger by a small hose. The degas bottle
collects coolant that expands with rising temperature,
and would otherwise overfl ow from the system. Coolant
level should be at or slightly above the "ADD" mark on
the bottle when the system is cold. Coolant should be
added ONLY to the bottle when the system cools. Add
specifi ed coolant as required.
DEGAS
BOTTLE
Figure 11-9 Checking Coolant Level (6.0L)
FLUSHING COOLING SYSTEM - SEA-WATER
SECTION
To prevent silt and/or salt build-up in the cooling system
(fresh or raw-water cooled), fl ush the sea-water section
of the cooling system with fresh water at specifi ed
intervals. Close seacock (if applicable) before removing
inlet hose.
CAUTION
Do not operate the engine without suffi cient amount
of water being supplied to the sea-water pump.
The sea-water pump impeller may be damaged and
subsequent overheating damage may result.
34
PRESSURE
CAP
L510010-11
CAUTION
Do not run the engine above 1500 RPM when
fl ushing. Suction created by the sea-water pump
may collapse the fl ushing hose, causing the engine
to overheat. Watch the temperature gauge while
fl ushing to ensure the engine does not overheat.
Figure 11-10 Typical Sea-Water Inlet

TESTING COOLANT FOR ALKALINITY

It is recommended that the coolant in the fresh-water
section be tested each year for alkalinity. Coolant
that is not alkaline has lost the effectiveness of its rust
inhibitors, which can lead to internal corrosion and
cooling system problems. It is recommended to replace
standard ethylene glycol coolant in the system every two
years or long life coolant, Dex-Cool™, every fi ve years
to prevent a build-up of harmful chemicals within the
fresh-water system.
WARNING
Do not remove cooling system fi ller cap when
the engine is hot. Allow the engine to cool and
then remove the pressure cap slowly, allowing the
pressure to vent. Hot coolant, under pressure, may
discharge violently and cause severe burns.
ATTACH
FLUSHING
ADAPTER
HERE