Kohler 27EFOZ, Service Manual

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TP-5936 7/04 14 Section 5 Cooling System
5.2 Water-Cooled Exhaust
Manifold
Each marine generator set has a water-cooled exhaust
manifold. The coolant solution circulates through the
manifold, reducing the amount of heat radiated from the
exhaust into the surrounding area.
The engine thermostat is located in the water-cooled
exhaust manifold. See Section 1 for the thermostat
location. See Figure 5-2 and Figure 5-3 for exhaust
manifold bolt tightening sequence and torques.
Model Bolt Torque
32EOZ/27EFOZ 19 Nm (14 ft. lbs. )
Figure 5-2 Water-Cooled Exhaust Manifold Bolt
Tightening Torques
344848-E
1
2 3 6
5 4 7
8
Figure 5-3 Water-Cooled Exhaust Manifold Bolt
Tightening Sequence
5.3 Closed Heat Exchanger
In a closed cooling system, the seawater circulates
through separate chambers within the heat exchanger
to cool the engine coolant. The seawater then mixes
with engine exhaust and ejects out the exhaust outlet.
See Section 1.2 for the coolant capacities; include
coolant recovery tank capacity of 0.24 L (8.0 oz.). See
Section 1.2 for the thermostat and pressure cap ratings.
Note: Use antifreeze capable of withstanding the
lowest possible temperatures.
5.4 Check and Fill the Cooling
System
Before filling the cooling system, close all the petcocks
and tighten all of the hose clamps. Use a solution of 50%
ethylene glycol and 50% fresh, softened water to inhibit
rust/corrosion and prevent freezing.
Add additional
coolant, as necessary, to the coolant recovery tank.
Maintain the level in the coolant recovery tank at
approximately 1/4 full. Periodically check the coolant
level on closed systems by removing the pressure cap.
Do not rely solely on the level in the coolant recovery
tank. Add fresh coolant until the level is just below the
overflow tube opening.
5.5 Flush and Fill the Cooling
System
For optimum protection drain, flush and refill the cooling
system at the interval listed in the service schedule.
1. Open the petcocks located at the heat exchanger,
engine block, and cooling system and let the
system drain completely. The petcocks on some
models are located behind the belt guard. Remove
the pressure cap to simplify draining.
2. Drain, clean, and flush the coolant recovery tank.
3. Flush the cooling system with clean water.
4. Fill the cooling system with recommended coolant.
Note: Pay special attention to the coolant level. After
the coolant drains, allow time for complete refill of
the engine water jacket. Check coolant level as
prescribed in the prestart checklist in the
operation manual.