Holiday Neptune 2004, Owner'S Manual

Page: 389 / 416

CHASSIS INFORMATION --- SECTION 10 • 389
NEPTUNE 2004
10
Rotten, swollen and worn hoses, as well as loose connections, are frequent causes
of coolant system problems. Overheating can be caused by a collapsed hose or a clog
caused by rubber shedding from a rotten hose. Replace any hose found to be
cracked, swollen or damaged. Connections should be inspected periodically and
hose clamps tightened.
If the coolant system becomes frozen solid, place the motorhome in a warm
area until the ice is completely thawed. At this point the motorhome must be
towed. If the engine is operated when the cooling system is frozen it will result in
engine overheating due to insufficient coolant.
Once thawed, check engine, radiator and related components for damage
caused by expansion of frozen coolant.
If the engine is overheated, never pour cold coolant into a hot engine. The sudden
change in temperature may crack the cylinder head or block. If the engine is hot, fill
slowly to prevent rapid cooling and distortion of engine castings.
The diesel engine uses compression to ignite
the fuel/air charge. To increase compression
inside the combustion chamber (resulting in
increased power output) a turbocharger is added
to the engine. The turbocharger is a paired
housing assembly with impellers inside each
housing connected by a common shaft. One
impeller is propelled by the engine exhaust,
which drives the other impeller. The function of
the other impeller is to increase compression
inside the combustion chamber by forcing air
into the intake manifold. The intake air charge is
heated two different ways: through convection
by the exhaust gases driving the turbocharger,
and any time air is compressed heat is produced.
This has a negative effect inside the combustion
chamber resulting in lost power potential.
Therefore, a Charge Air Cooler (CAC) is
installed to cool the intake air before it enters the
engine. The CAC may be mounted to either the
top or side of the radiator.
The CAC performs the same function as a radiator,
cooling air instead of liquid. Ambient air passing
through the CAC will cool the engine's intake air
charge.
Coolant Hoses
Coolant System
- Thawing
CHARGE AIR COOLER
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