- The type of fuel that is used
- The viscosity of the engine oil
- The operation of the glow plugs
- Optional Cold starting aid
- Battery condition
Refer to Special Publication, SEBU5898, "Cold Weather Recommendations for Caterpillar Machines".
This section will cover the following information:
- Potential problems that are caused by cold-weather operation
- Suggest steps which can be taken in order to minimize starting problems and operating problems when the ambient air temperature is between
0° to −40 °C (32° to -40 °F) .
The operation and maintenance of an engine in freezing temperatures is complex . This complexity is because of the following conditions:
- Weather conditions
- Engine applications
Recommendations from your Cat dealer are based on past proven practices. The information that is contained in this section provides guidelines for cold-weather operation.
Hints for Cold Weather Operation
- If the engine will start, operate the engine until a minimum operating temperature of
80° C (176° F) is achieved. Achieving operating temperature will help prevent the intake valves and exhaust valves from sticking. - The cooling system and the lubrication system for the engine do not lose heat immediately upon shutdown. This means that an engine can be shut down for a period and the engine can still start readily.
- Install the correct specification of engine lubricant before the beginning of cold weather.
- Check all rubber parts (hoses, fan drive belts) weekly.
- Check all electrical wiring and connections for any fraying or damaged insulation.
- Keep all batteries fully charged and warm.
- Fill the fuel tank at the end of each shift.
- Drain the water from the fuel system. Refer to this Operation and Maintenance Manual, "Fuel System Primary Filter/Water Separator - Drain".
- Check the air cleaners and the air intake daily. Check the air intake more often when you operate in snow.
- Ensure that the glow plugs are in working order. Refer to Troubleshooting , "Glow Plug Starting Aid - Test".
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Personal injury or property damage can result from alcohol or starting fluids. Alcohol or starting fluids are highly flammable and toxic and if improperly stored could result in injury or property damage. |
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Do not use aerosol types of starting aids such as ether. Such use could result in an explosion and personal injury. |
- For jump starting with cables in cold weather, refer to the Operation and Maintenance Manual, "Starting with Jump Start Cables." for instructions.
Viscosity of the Engine Lubrication Oil
Correct engine oil viscosity is essential. Oil viscosity affects the amount of torque that is needed to crank 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 (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 110V dc or 240V dc. The output can be 750/1000W. Consult your Cat dealer for more information.
After starting the engine, the engine speed will be held at low speed. The time held at low speed will depend on ambient temperature and time since last run. The procedure is in order to allow the engine systems to stabilize. When idling after the engine is started in cold weather, increase the engine rpm from 1000 to 1200 rpm. This increase in RPM 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
Recommendations for Coolant Warm Up
Warm up an engine that has cooled below normal operating temperatures due to inactivity. This procedure 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 burned completely 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.
Starting and stopping an engine many times without being operated in order to warm up completely, the carbon deposits become thicker. This carbon 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
The engine must be thoroughly warmed in order to keep other engine parts in better condition. Also, 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 improvement 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 Coolant Temperature Regulator and Insulated Heater Lines
The engine is equipped with a coolant 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 system ensures that coolant flows around the engine under cold operating conditions. The coolant temperature regulator begins to open when the engine jacket coolant has reached the correct minimum operating temperature. As the jacket coolant temperature rises above the minimum operating temperature, the coolant temperature regulator opens further allowing more coolant through the radiator. This action allows the dissipation of excess heat.
The progressive opening of the coolant temperature regulator operates the progressive closing of the bypass passage between the cylinder block and head. This process ensures maximum coolant flow to the radiator in order to achieve maximum heat dissipation.
Note: Do not restrict the air flow. Restriction to the air flow can damage the fuel system. Caterpillar strongly discourages the use of all air flow restriction devices such as radiator shutters. Restriction of the air flow can result in the following: high exhaust temperatures, power loss, excessive fan usage and reduction in fuel economy.
A cab heater is beneficial in very cold weather. The feed from the engine and the return lines from the cab should be insulated in order to reduce heat loss to the outside air.
Insulating the Air Inlet and Engine Compartment
When temperatures below
Additional heat can be retained around the engine by insulating the engine compartment.
Recommendation for Crankcase Breather Protection
Crankcase ventilation gases can contain a large quantity of water vapor. This water vapor can freeze in cold ambient conditions and can plug or damage the crankcase ventilation system.
The breather heater or other breather thermal protection is important and any OEM equipment must be operational to prevent the risk of breather freezing for operation below