Charge Air Cooler - Monaco DIPLOMAT 2004 Owner's Manual

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.
After leaving the turbocharger, intake air is compressed and heated to approximately
300º to 375º F., depending on the engine load and throttle position. Before the air enters
the intake manifold, the CAC cools the intake air temperature to the engine manufacturer's
specifications. Lower intake air temperatures reduce exhaust emissions, improve fuel
economy and increase horsepower. The CAC will continually expand and contract up to
¼" as throttle increases and decreases.
Visually inspect the charge air cooler, every six months, for dirt and debris that
may be blocking the fins. If the motorhome develops an oil leak, there is a possi-
bility that the oil will coat the fins of the CAC. Dust will adhere to the oil film and
eventually clog the fins greatly reducing cooling efficiency. When the oil leak is
repaired, the CAC must be thoroughly cleaned.
Rear mounted radiators, with a top mounted CAC, will require more frequent visual
inspections than a side mounted CAC. Litter and dust along the roadway can restrict the
airflow on this type of system. During each oil change inspect the engine side of the
radiator/CAC assembly for foreign objects that may be causing restriction.
Spraying degreaser on the charge air cooler, as well as using a steam cleaner, will not
damage the CAC. However, pressure washer and steam cleaner nozzles placed too close to
the CAC can bend the fins. The recommended cleaning procedure for the CAC, and the
radiator, is to use a bucket of mild soap and water. Carefully wash with a bristle brush then
rinse using a garden hose, with minimum water pressure, standing back a distance to avoid
bending the fins.
CHASSIS INFORMATION
DIPLOMAT 2004

CHARGE AIR COOLER

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