Onan MDJE Service Manual

The sea water side of the heat exchanger should be
inspected and cleaned on a yearly basis. Remove the
two end caps and flush out any deposits that may
have accumulated in the tubes. Be certain to note the
position of the gaskets when removing the heat
exchanger ends. On some models the gaskets direct
the water flow and when replaced must be positioned
the same way they were when removed.
Captive Water Side
The captive water side of the heat exchanger should
be protected from corrosion and scale formation by
filling theenginecooling system with
a50/50 mixture
of antifreeze and water. If not protected, rust and
scale will form on the walls of the engine water jacket.
The rust and scale will combine to form an insulation
layer on the water jacket which will reduce the
efficiency of heat transfer to coolant.This can lead to
overheating and subsequent damage to the engine.
Rusty water or rusty solutions of antifreeze indicate
the formation of rust on the water jacket. If this is the
case, the engine water jacket and heat exchanger
should be cleaned and thoroughly flushed out, as
described
in the MAlNTENANCf section. Use a
chemical cleaner to remove rust and scale deposits,
following the procedure recommended by the sup-
plier.
KEEL COOLERS
Keel cooling (see Figure 17) is available as an option
on the
MDJA, MDJB, MDJC, MDJE, and MDJF
generator sets. The captive water pump, mounting
bracket, belt guard, hose, and fittings are supplied by
Onan. Somesetsmay also haveasea water pump for
injecting water into the exhaust system, while other
sets may use a
dry stack exhaust. The keel cooler,
expansion tank, and plumbing must be supplied by
customer.
The keel cooler should be protected from corrosion
and scale formation by filling the engine cooling
system with a
50/50 mixture of antifreeze and water.
Follow the same service procedures recommended
for the captive water side of heat exchangers (see
previous section) to remove rust or scale formations.
With some keel cooler systems, a sea water pump
is
used for injecting water into the exhaust system.
Check the water filter after every
100 hours of
operation. Change sooner if the unit is used under
exceptionally dirty water conditions. When the boat
is dry docked, inspect the keel cooler and remove any
accumulation of sediment or debris.
TANK -
EXPANSION
FIGURE 17. KEEL COOLER INSTALLATION
23
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Onan MDJE Specifications

General

Brand	Onan
Model	MDJE
Category	Engine
Language	English