Air Filter; Changing The Filter; Air Filter Minder; Diesel Particulate Filter - Holiday Rambler Imperial 2008 Owner's Manual

AIR FILTER

Changing the Filter

The entire air fi lter cartridge is discarded
and replaced by loosening the inlet and outlet
ducting clamps and releasing the retaining band
snaps. The air fi lter is located in the engine
compartment. The Air Filter Minder will
indicate when the fi lter will need to be changed.

Air Filter Minder

The air fi lter minder, located in the roadside of
the engine compartment, is a precision overfl ow
restriction gauge designed to take the guesswork
out of air cleaner replacement.
As dirt captured by
the fi lter cartridge
slowly builds up,
vacuum between the
fi lter and charge air
cooler increases. The
indicator locks at the
point of maximum
restriction so readings
can be taken with or
without the engine
running.
When the desired change-out point is reached,
the air fi lter should be replaced and the service
indicator reset by pushing the Reset button on
the bottom of the minder.

DIESEL PARTICULATE FILTER

The exhaust system is equipped with a DPF
(Diesel Particulate Filter) to lower particulate
emissions. The DPF traps particulate matter.
Naturally occurring exhaust heat oxidizes
built up particulate and regenerates the fi lter.
This is called passive regeneration. If passive
regeneration is not suffi cient, an active
regeneration cycle will automatically initiate at
speeds greater than 20 mph. Both passive and
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active regeneration cycles automatically initiate.
WARNING:
Use Ultra Low Sulfur Diesel (ULSD)
only. Do not use Low Sulfur Diesel
(LSD) with a DPF equipped engine.
LSD will damage the DPF, which may
cause the Stop Engine light to illuminate
and cause the engine to severely derate.
Passive Regeneration:
Passive regeneration uses heat from naturally
occurring exhaust gasses to oxidize built-up
particulate.
Active Regeneration:
An active regeneration cycle will initiate if
exhaust temperatures are not high enough to
regenerate the fi lter. The motorhome must be
traveling in excess of 20 mph for an active
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regeneration cycle to initiate.
20 0 8 I M P E R I AL
CHASSIS INFORMATION — 10
During an active regeneration cycle, diesel
fuel is introduced into the exhaust system
upstream of the DPF. The fuel will ignite and
super-heat the DPF to oxidize particulate matter.
The HEST (High Exhaust
System Temperature) dash
light will illuminate when
exhaust temperatures reach
1450º F., indicating that
an active regeneration is
underway and exhaust
system temperatures are
elevated above normal
levels. These temperature levels may occur
for up to 40 minutes. The HEST light will
remain on until the exhaust temperature cools
to 650º F., which may not be until the engine is
turned off and the exhaust system cools before
restarting. The HEST light does not indicate a
fault as long as there are no other active warning
lights.
CAUTION:
Use extreme caution if parking
the motorhome during an active
regeneration cycle. The exhaust system
and exhaust gas will be extremely hot
to the point of fire hazard. Do not park
the motorhome on or around anything
combustible.
NOTE:
If the engine is turned off during an
active regeneration cycle, the cycle will
automatically begin again (if necessary)
when the motorhome is operated at
speeds above 20 mph.
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HEST Dash Light
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