Monaco 2002 Diplomat, Service Manual

Page: 286 / 324

Viscosity:
Viscosity is simply a measure of resistance of molecule layers moving
relative to an adjacent layer. All fluid viscosity are 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 reducing
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 have
no suffix. When a lubricating oil meets both high and low temperature
requirements they are classified as multi-viscosity or multigrade.
Routine Maintenance Recommendations:
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
performance classification and the engine duty cycle. Refer to
the Cummins Operation & Maintenance Manual for complete
details.
It is possible to operate diesel engines in extremely cold environments.
The engine should be properly prepared and maintained. The correct lubricants,
fuels and coolant MUST be used for the cold weather range for which the
motorhome is being operated. Cold weather operation can be defined in two
categories:
Winter and Arctic .
WINTER (32º to -25º F) (0º to -32º C): Use a 50% antifreeze to 50%
water coolant mixture, use multi-viscosity oil meeting Cummins specifications
and fuel to have maximum cloud pour points 10º F (6º C) lower than the
ambient temperature in which the motorhome operates.
ARCTIC (-25º to -65º F) (-32º to -52º C): Use a 60% antifreeze to 40%
water coolant mixture. Use oil meeting Cummins specifications and fuel to
have maximum cloud pour points 10º F (6º C) lower than the ambient
temperature in which the motorhome operates.
Refer to the Operations & Maintenance Manual for more
detailed information.
Chassis Information
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
D I P L O M A T
1 0 • 2 8 6
Oil
Recommendations -
Cold Weather