Viscosity of the Engine Lubrication
Oil
Correct engine oil viscosity is essential. Oil viscosity
affects lubrication properties and wear protection that
the oil provides for the engine. Refer to this Operation
and Maintenance Manual, “Fluid Recommendations”
for the recommended viscosity of oil.
Recommendations for the Coolant
Provide cooling system protection for the lowest
expected outside temperature. Refer to this
Operation and Maintenance Manual, “Fluid
Recommendations” for the recommended coolant
mixture.
In cold weather, check the coolant often for the
correct glycol concentration in order to ensure
adequate freeze protection.
Engine Block Heaters
Engine block heaters (if equipped) heat the engine
jacket water that surrounds the combustion
chambers. This heat provides the following functions:
• Startability is improved.
• Warm up time is reduced.
An electric block heater can be activated once the
engine is stopped. A block heater can be 110 V dc or
240 V dc. The output can be 750/1000W. Consult
your Perkins dealer or your Perkins distributor for
more information.
Idling the Engine
When idling after the engine is started in cold
weather, increase the engine rpm from 1000 to 1200
rpm. This idling will warm up the engine more quickly.
Maintaining an elevated low idle speed for extended
periods will be easier with the installation of a hand
throttle. The engine should not be “raced” in order to
speed up the warm-up process.
While the engine is idling, the application of a light
load (parasitic load) will assist in achieving the
minimum operating temperature. The minimum
operating temperature is 80° C (176° F).
Recommendations for Coolant
Warm Up
Warm up an engine that has cooled below normal
operating temperatures due to inactivity. This warm
-up should be performed before the engine is
returned to full operation. During operation in very
cold temperature conditions, damage to engine valve
mechanisms can result from engine operation for
short intervals. This damage can happen if the engine
is started and the engine is stopped many times
without being operated in order to warm up
completely.
When the engine is operated below normal operating
temperatures, fuel and oil are not completely burned
in the combustion chamber. This fuel and oil causes
soft carbon deposits to form on the valve stems.
Generally, the deposits do not cause problems and
the deposits are burned off during operation at normal
engine operating temperatures.
When starting and stopping an engine many times
without being operated in order to warm up
completely, the carbon deposits become thicker. This
starting and stopping can cause the following
problems:
• Free operation of the valves is prevented.
• Valves become stuck.
• Pushrods may become bent.
• Other damage to valve train components can
result.
For this reason, when the engine is started, the
engine must be operated until the coolant
temperature is 80° C (176° F) minimum. Carbon
deposits on the valve stems will be kept at a minimum
and the free operation of the valves and the valve
components will be maintained.
The engine must be thoroughly warmed in order to
keep other engine parts in better condition. The
service life of the engine will be generally extended.
Lubrication will be improved. There will be less acid
and less sludge in the oil. This condition will provide
longer service life for the engine bearings, the piston
rings, and other parts. However, limit unnecessary
idle time to 10 minutes in order to reduce wear and
unnecessary fuel consumption.
The Water Temperature Regulator and
Insulated Heater Lines
The engine is equipped with a water temperature
regulator. When the engine coolant is below the
correct operating temperature, jacket water circulates
through the engine cylinder block and into the engine
cylinder head. The coolant then returns to the cylinder
block via an internal passage that bypasses the valve
of the coolant temperature regulator. This return
ensures that coolant flows around the engine under
cold operating conditions. The water temperature
regulator begins to open when the engine jacket
water has reached the correct minimum operating
temperature. As the jacket water coolant temperature
rises above the minimum operating temperature, the
water temperature regulator opens further allowing
more coolant through the radiator to dissipate excess
heat.
The progressive opening of the water temperature
regulator operates the progressive closing of the
bypass passage between the cylinder block and
head. This action ensures maximum coolant flow to
the radiator in order to achieve maximum heat
dissipation.
SEBU8731
47
Cold Weather Operation
Cold Weather Operation
