Monaco 2002 Diplomat, Service Manual

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Synthetic oils API category III specifications are recommended for
extreme cold temperatures only.
Low viscosity oils used for winter operations will aid in starting.
Synthetic oils or oil with adequate low temperature properties used for Arctic
operations, where the engine cannot be kept warm when shut down, will aid
in starting.
The use of synthetic oils should not be used to extend drain intervals.
Extended oil change intervals can decrease engine life and possibly affect the
engine warranty.
Oil additives should not be used unless the oil supplier or oil manufacturer
has been consulted and provided positive evidence or data establishing
satisfactory performance in the engine.
Function of Engine Oil:
If a lubricating oil is to work in an engine it must be capable to perform
various functions. Lubrication of the moving parts is the primary function.
The lubricating oil should be able to form a film between metal surfaces
preventing metal to metal contact and reducing friction. When you have a
metal to metal contact, friction heat is generated. Welding of the part can
occur and metal transfer will result in scuffing or seizing. The film of oil
contacting the surfaces will provide cushioning and shock dampening as well.
Cleaning is another function. The oil should perform as a cleaner in the
engine by flushing contaminates from critical components. These contaminates
should be removed in the filtration system or during the course of an oil
change. Oil will provide a protective barrier to prevent corrosion of non-like
metals.
Internal components of the engine require cooling. The primary coolant
system cannot provide this cooling. Oil will transfer heat by contacting the
various components then transferring to the primary cooling system at the oil
cooler. The uneven surfaces are filled to react as a combustion seal within
the cylinder liner and other internal components.
Synthetic Engine Oil:
In extreme environments where ambient temperatures can be as low as
-45º C (-50º F) a petroleum based oil will not perform satisfactorily in diesel
engines. Synthetic oils were developed for these type applications. These
synthetic oils are blend from ether and/or hydrocarbon based oils. These base
oils are produced by chemically reacting lower molecular weight materials to
manufacture lubricants of desired properties. All synthetic based oils must
meet the API category III classifications and SAE viscosity grades. Synthetic
oils and petroleum based oils should never be mixed.
Chassis Information
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