Routine Oil Maintenance; Viscosity - Monaco DIPLOMAT 2004 Owner's Manual

Viscosity:

Viscosity is simply a measure of resistance of molecule layers moving
relative to an adjacent layer. All fluid viscosity is affected by temperature. A
multigrade lubricating oil tends to be less sensitive to temperature changes
due to formulation. Lubricating oils are generally selected for use with
viscosities appropriate for the expected operating temperature. The correct
selection of a lubricating oil of correct viscosity is critical for optimum
performance. Some effects of incorrect viscosity when the oil is too thick
range from difficulty in starting, to increasing fuel consumption and
reduced power output. When the oil is too thin, oil consumption is increased
as well as wear from the metal to metal contact. This will also increase
engine noise.
Low temperature viscosity specifications are identified by a "W" (winter).
High temperature viscosity that meets the 100º C (212º F) requirements has
no suffix. When lubricating oil meets both high and low temperature
requirements they are classified as multi-viscosity or multigrade.
1. Check oil level daily.
2. Replace oil filter at every oil drain interval.
3. Cummins Engine Company, Inc. recommends the use of high
quality, API (American Petroleum Institute) licensed CH-4 or
CES20071, 15W-40, multiviscosity oil or premium oil.
4. The recommended oil drain interval is defined by the API oil per-
formance classification and the engine duty cycle. Refer to the
Cummins Operation & Maintenance Manual for complete
details.
To change oil start with the motorhome at normal operating temperature.
Park on a level surface and stop the engine. Remove the two crankcase
drains plugs from both the deep and shallow portions of the oil pan to allow
the oil to drain. Install the drain plugs back into the oil pan and tighten to 40
to 60 ft-lbs. Remove the oil filter.
NOTE: It is recommended that the used oil filter be opened
and the element examined for excessive wear particles; see the
OEM Engine Manual for information on this procedure.
Wipe the filter base sealing surface and ensure that the old gasket is
removed. Apply clean engine oil to the gasket of the new filter and install the
filter until the gasket contacts the filter base. Tighten the filter an additional ¾
turn. Do not over-tighten. Remove the oil filler cap located at the rear of the
engine. Fill the crankcase with the amount of oil determined by dipstick
readings (about 20 quarts).
CHASSIS INFORMATION
DIPLOMAT 2004
Routine Oil
Maintenance
10 • 401