Service Bulletin

Operation of Diesel Engines in Cold Climates

Satisfactory performance of a diesel engine in cold and arctic climates requires modification to the engine support systems, operating practices, and maintenance procedures. Everyone involved with equipment in these climates must address the fact that cold climates will have an effect on the starting, performance and reliability of the equipment as well as the engine. The reliability of the engine and equipment will be seriously impaired if not properly prepared for the environment in which it is operating. To winterize equipment there are three objectives: [*]Reasonable starting characteristics followed by practical and dependable warm-up of engine and equipment[*]A unit or installation needs to be as independent as possible from other external influences[*]Modifications which maintain satisfactory engine operating temperatures with a minimum increase in maintenance of the equipment and accessories. [/ol] As the operating climate becomes colder, an increasing amount of equipment modifications are required for satisfactory performance. The engines must be capable of operating in all climate extremes with satisfactory performance and durability. Some cold climates problems are listed below. While this list contains problems as a result of cold temperatures, it must be stressed that potential problems can occur which are in addition to those contained in this list.

Engine Idle It is not recommended that the engine be operated at an idle no load condition for prolonged periods (above 15 minutes) of time. Operating engines at idle (650 to 1000 rpm) in cold ambient temperatures wastes fuel, accelerates wear, and can result in serious engine damage. Under these low temperature conditions, incomplete combustion will occur, allowing deposits of unburned tars and carbon to build-up on the valve guide and valves and eventually cause valve sticking. At low idle (650 to 700 rpm) there will be insufficient coolant flow and coolant temperature at the cab heater to maintain adequate cab heat. In low ambient temperatures, if radiant and convection heat losses are not prevented, the engine will not consume an adequate amount of fuel to maintain coolant and combustion temperatures. Sufficient support systems are recommended to preclude the necessity to idle engines for prolonged periods. It is recognized that regardless of recommendations, operators will idle engines for prolonged periods, especially if the driver is sleeping in the cab compartment of the chassis. If the operator insists on prolonged idling, it is recommended that the engine be idled at an rpm which is adequate to maintain coolant temperatures above 60°C [140°F]. In minus 18°C [0°F], the engine will need to be idled above 1200 rpm. For this type of operation, a full on-off type fan and winter front must be used. The thermostat, thermostat seal and the deaerating system must not allow coolant leakage through the radiator core with the thermostat in the closed position.

Electrical Systems The normal source of energy used to crank an engine is a battery. As the battery temperature decreases, the battery's capacity to produce power is lowered and its ability to recover power is slower. The engine's cranking load increases as the ambient temperature decreases compounding the battery power loss problem. Engine manufacturers normally recommend battery and electrical system capacity for specific engine families to provide an adequate start at minus 18°C [0°F]. For satisfactory operation in colder ambients, the batteries need to be heated to restore their original cranking capacity, or more batteries need to be added. Adequate battery capacity results in low cranking speed. Cranking speed continues to slow down during the cranking cycle and can progress to the point where the engine will not start. The wire size, length and connections of the starter circuit determine the ability of the battery to freely transmit power to the starter. Undersized wire acts as a restriction to flow of electrical power. Loose or corroded wires and connections can consume up to 50 percent of more of the available battery power before is gets to the starter. An electric starter simply receives electrical energy and converts it to mechanical energy. The peak efficiency of the starter occurs at engine cranking speeds of between 100 to 150 rpm. At lower speeds the efficiency drops off and current flow increases. If the starter is allowed to stall, and the engine will not start, 100 percent of the electrical energy turns to heat and will burn up the starter and wiring. If cranking speeds are continuously low, either more energy (battery capacity), higher starter torque or less cranking load is required. Fuels The free flow of diesel fuel depends on its temperature, pour and clouds points. The phenomenon of fuel thickening in cold environments is referred to as waxing. The temperature at which this wax forms varies with the base stock of fuel. If the engine is operating below the cloud point of the fuel, the wax crystals circulated with the fuel will clog screens, filters, or restrict the fuel lines at the sharp bends, fittings etc. Pour point depressants only reduce the size of the wax crystals in the fuel, they do not alter the temperature at which the wax crystals form. The only known method to prevent wax formation in fuels is to use a lower cloud point fuel or maintain the temperature of the fuel above the cloud point. This can be accomplished by using fuel heaters whether the engine is running or is not running. When fuel heaters are used, they must be selected to maintain fuel temperatures above the cloud point but below the point at which the lubricating quality of the fuel decreases. Selected fuel heaters or filters for any given engine ought not impose a restriction to the fuel system that exceeds 100 mm Hg [4 in Hg] when measured at the fuel pump inlet. Blending fuels (such as Number 1 fuel with Number 2 fuel) while reducing the wax point also reduces the BTU content of the fuel, increasing fuel consumption. Blending also reduces the lubricating quality of the fuel which reduces the life of the fuel system components. WARNING[/align]
Do not use alcohol or gasoline as a fuel blending agent. They can be unstable under certain conditions and be hazardous or explosive when mixed with diesel fuel.

[/align] Lubricating Oils Two physical properties-viscosity and pour point are vital to the lubrication of the engine during cold start up. Viscosity is the most important. The lubricating oil must pour freely from its containers and it must circulate freely throughout the engine. Although it is possible to start an engine when the oil has solidified in the crankcase, doing so can result in catastrophic engine shutdown due to lack of lubrication. There are cold climate operation lubricating oils with a sufficiently low pour point available that will remain in a liquid state at the minimum expected temperatures. The viscosity of the oil controls engine friction and oil circulation. Oil viscosity influences the following performance factors. [*]Starting and warm up[*]Power output[*]Fuel consumption[*]Engine cooling[*]Starting wear[*]Oil consumption[*]Engine cooling[*]Engine noise [/ol] The first five performance factors are improved by using a low viscosity oil, while the last three factors are improved with a high viscosity oil. Lubricating oil viscosity is one of the most critical factors in engine startability. If the viscosity is too high, the resistance to cranking ability is too high for the engine to reach an acceptable cranking speed. It is necessary to heat the engine lubricant before starting the engine if the lubricant that is used does not have the proper pour point or viscosity. Heating the lubricant will decrease its viscosity, therefore, increasing lubrication and reducing friction during cranking. All filters ought to be located within the confines of the engine compartment so the heat of the engine can be used to prevent gelling of the lubricants. Air Intake Systems There are two aspects of intake air which must be taken into consideration when winterizing a vehicle. These considerations are air density and temperature. Air Density Air density increases as ambient temperature decreases. The net result in a turbocharged engine is that the peak cylinder pressure increases. An increase of cylinder pressure can contribute to the following types of problems. [*]Blocks cracking[*]Blown head gaskets[*]Excessive crankshaft bearing loading[*]Camshaft break down when hydraulic engine brakes are used[*]Loosening or breaking of head bolts[*]Piston ring beat in[*]Cracked pistons [/ol] Air Temperature There is a direct correlation between intake air temperature and combustion temperature. One of the end results of a diesel engine with cold intake temperatures is that combustion temperatures will be reduced. At reduced combustion temperature, the low ends of the diesel fuel do not burn. These unburned heavy ends of the fuel will deposit a tar-like varnish substance on the valve guides and valve stems and cause them to stick in the open position. When the open valves and pistons meet, a break down occurs. Cold intake air temperatures will also result in detonation (uncontrolled combustion) and piston burning. Below 0°C [32°F], it is recommended that intake air come from inside the engine enclosure. This will provide warm air to the intake and reduce engine heat loss. If the air cleaner is not located within the engine compartment enclosure, then ducting must be routed from the engine compartment to the air cleaner inlet. Adequate sealing of the engine compartment is necessary. Side curtains alone are not always satisfactory. If there are openings around the radiator cowl and underneath the engine, these areas must also be sealed. Depending on ambient temperature and engine compartment size, heat the air within the engine compartment to maintain combustion temperatures. An aftercooled engine will perform well in these conditions, as the cooler element which normally cools heated air down to near the level of the coolant temperature, will warm cold intake air up to near the coolant temperature. It is extremely beneficial to provide a temperature controlled on-off type fan so the radiant and convection heat within the engine compartment is not dissipated by air flow. Cooling System CAUTION[/align]
Do not use ether with glow plug starting aids as engine damage can occur.[/align]
Coolant within a diesel engine is primarily used as a heat transfer media and is subject to freezing in cold and Arctic climates. The lowest freezing temperature that can be provided for the coolant is obtained by using a solution of approximately 60 percent ethylene glycol and 40 percent water. This mixture will turn to slush at about -50°C [-60°F] . It is necessary to heat the coolant or use a starting aid (S.A. ether) in climates of -1° to 10°C [30° to 50°F] and colder to get a successful start. In climates colder than -23°C [-10°F] it is recommended that coolant heaters be used in conjunction with ether starting aids. There are three basic types of coolant heaters available in the marketplace. The heaters selected ought to maintain the coolant temperature to a minimum of 50°C [120°F] in any temperature encountered. [ul][*]Immersion Heaters [ul][*]Immersion heaters have a heating element immersed within the confines of the engine coolant passage. Heat is transferred to the cylinder liners and block via the coolant. Due to space limitations, the wattage is limited to 2500 watts each or less. An external electrical source is required to operate the heaters.[/ul][*]Tank Type Heaters [ul][*]Tank type heaters function on the convection principal. That is, a volume of coolant is heated within a small tank and then the heated coolant is circulated through the engine via the hose connections (similar to a percolator coffee pot). There are heaters available from 1000 to 4000 watts. An external electrical source is required for this type of heat. There are also tank type heaters with recirculating pumps which continuously circulate the heated coolant through the engine systems.[/ul][*]Fuel Burning Coolant Heaters [ul][*]Fuel burning coolant heaters are designed to burn liquid/vapor type fuels and some will operate on a mixture of fuels. The most common fuel burning heaters normally use diesel fuel, propane or gasoline. These are furnace gun type heaters where fuel is ignited via an igniter and the fuel is then sprayed on a transfer media such as a porous ceramic disc. This flame then heats the coolant via coils contained within the heater and transferred to the engine either by convection or by recirculating pumps incorporated into the heaters. These types of heaters are available in sizes from 6000 to 82000 BTU. Exhaust gases from these heaters can be used to heat engine compartments and accessories such as batteries.[/ul] [/ul] Coolant Flow The minimum amount of coolant that has to be heated for maximum efficiency of the heaters is the volume of coolant in the block and accessories in the coolant bypass system. To achieve this condition, the thermostats and thermostat seals must not allow coolant to flow through the radiator when the thermostat is closed. To check for coolant leakage past the thermostat seal and/or thermostat: [*]Remove engine outlet hose at the thermostat housing. Hold the hose in the air above the radiator baffle level, and run engine against the governor. If water comes out of the water outlet connection, the thermostat and/or seal is leaking. Ninety-seven percent of the time, it is the seal or debris keeping the thermostat open.[*]If coolant does not reach thermostat opening temperature, changing the thermostat will not correct the problem. [/ol] The second critical area for cold operating engines is coolant flow through the radiator core when the thermostat is in the closed position. A properly functioning deaeration system must be incorporated and there ought to be no reverse flow of coolant through either the fill line or the radiator. The deaeration baffle must not leak and must not have vent holes. To check for this condition: [*]Drain cooling system[*]Remove make up (fill line) at water pump and the plug end[*]Fill area above baffle with coolant. If water leaks through the drain **** of radiator, remove tank and repair. Coolant can be leaking through core vent tube which can have to be extended in expansion area. [/ol] Radiator Shutters When they are closed, radiator shutters prevent air flow across the radiator core as well as the engine. Air flow across the engine can extend warm-up time and prevent the coolant from reaching minimum operating temperatures in extremely cold ambient temperatures. The two most commonly used terms associated with the preparation of equipment for low temperature operation are Winterization and Arctic Specifications. Winterization of the engine and/or components so starting and operation are possible in the lowest temperature to be encountered requires: [*]Use of correct materials. (Some materials get brittle and fail at low temperatures.)[*]Proper lubrication, low temperature lubricating oils.[*]Protection from the low temperature air. The metal temperature does not change as a result of air flow, but the rate of heat dissipation is significantly increased by the flow of cold air over the exposed surfaces.[*]Fuel of proper grade for lowest operating temperature.[*]Heating to be provided to increase engine block and component temperature to a minimum of -23°C [-10°F] for ether aided starting in lower temperatures.[*]Proper external heating source available.[*]Electrical equipment capable of operating in lowest expected temperature. [/ol] Arctic Specifications refer to the design material and specifications of components necessary for satisfactory engine operation in extremely low temperatures to -54°C [-65°F] . Contact Cummins®, or the equipment manufacturer to obtain the special items required. The Arctic Specifications listed on the following pages are only general guidelines. Fan Drive A temperature controlled fan drive can be used to reduce cold air circulation at the engine to help conserve compartment heat. These devices function by completely or partially disconnecting the fan from it's drive source at a specified temperature. Several types of fan drives are commonly available: viscous, thermatic and thermo-modulating. Equipment Preparation The amount of modification varies as the temperature changes. Therefore, the following tabulation of recommended equipment is grouped into three (3) temperature ranges. When equipment heaters are required as recommended in this bulletin, it is suggested that all system heaters (coolant, oil and intake air) be used. The following recommendations apply to all engine models, except as noted. [ul]Winterize 0°C to -23°C [32°F to -10°F] [*]Use Ethylene Glycol antifreeze to protect to -29°C [-20°F][*]Use multi viscosity oils meeting API, CC/CD specifications. See Bulletin 3379002.[*]Fuel to have maximum cloud and pour points 6°C [10°F] lower than ambient temperature in which engine operates. [/ul] [ul]Thermostat[*]Radiator Shutters[*]System to provide a recommended 150 rpm cranking speed at -23°C [-10°F] V6-378 and V8-555 require 180 rpm.[*]Starting aid: ether or manifold flame heater.[*]Provide for warmed intake air from engine compartment in temperatures below -12°C [10°F][*]Shorten breather tube to at least 12 inches above oil pan flange on highway applications for operations below -18°C [0°F] . [/ul] [ul]When Using Air Starters[*]Provide alcohol injector in air compressor system. [/ul] [ul]Coolant Heaters[*]Oil Heaters [/ul] [ul]Winterize -23°C to -32°C to [-10°F to -25°F][*]Use ethylene glycol antifreeze 50 percent, water 50 percent.[*]Use multi viscosity oil meeting CC/CD specifications. See Bulletin 3379002.[*]Fuel to have maximum cloud and pour points 6°C [10°F] (lower than ambient temperature in which engine operates. [/ul] [ul]Thermostat[*]Radiator shutters sealed around edge and adjusted to close tight or shutters plus radiator cover.[*]Winterized heavy duty 24 volts cranking system to provide a recommended 150 rpm cranking speed at -32°C [-25°F] after preheat. V6-378 and V8-555 require 180 rpm.[*]Starting aid: ether or manifold flame heater.[*]Provide for heated intake air using intercooler manifold, engine compartment enclosures with air cleaner intake air drawn from engine compartment.[*]Dry type air cleaner.[*]Shorten breather tube to at least 30 cm [12 in] above oil pan flange. [/ul] [ul]When Using Air Starters[*]Provide alcohol injector in air compressor system. [/ul] [ul]Coolant Heaters[*]Oil Heaters Oil heaters - If proper viscosity oil is not used.[*] Off/On type fan.[*] Oil pan shield for on-highway units. [/ul] [ul]Battery Warmer[*]Heavy duty arctic type batteries.[*]Battery cables size per Table 10,[*]All filters to be mounted in the engine compartment. Before exposing the equipment to the low temperature, change all filters, drain the systems and flush thoroughly with arctic fuels and lubricants.[*]Insulate all coolant, fuel, and oil lines exposed to the elements. [/ul] [ul]Arctic Specifications -32°C to -54°C [-25°F to -65°F][*]Use ethylene glycol antifreeze 60 percent, water 40 percent mixture.[*]Use Arctic oils meeting CC/CD specifications. See Bulletin 3379002.[*]Fuel to have maximum cloud and pour points 6°C [10°F] lower than ambient temperature in which engine operates. [/ul] [ul]Thermostat [*]Tight winter front cover for radiator in front of shutters.[*]Winterized heavy duty 24 volts cranking system to provide a recommended 150 rpm cranking speed at -32°C [-25°F] after preheat. V6-378 and V8-555 require 180 rpm.[*]Starting aid: ether or manifold flame heater.[*]Provide for heated intake air using intercooler manifold, engine compartment enclosures with air cleaner intake air drawn from the engine compartment.[*]Dry type air cleaner. Install in engine compartment.[*]Shorten breather tube to at least 30 cm [12 in] above oil pan flange. [/ul] [ul]When Using Air Starters[*]Provide alcohol injector in air compressor system. [/ul] [ul]Coolant Heaters[*]Oil heaters - If proper viscosity oil is not used.[*]Off/On type fan.[*]Insulated cover for lower part of the engine compartment including oil pan shields. [/ul] [ul]Battery Warmer[*]Heavy duty arctic type batteries.[*]Battery cables size per Table 10. Hold circuit wiring short as possible.[*]All filters to be mounted in the engine compartment. Before exposing the equipment tot he low temperature, change all filters, drain the systems and flush thoroughly with arctic fuels and lubricants. Replace the filter a second time after the flushing operation.[*]Repack fan hub and water pump with arctic grease.[*]Winterize mechanical controls and instruments: [ul][*]tachometer[*]tachometer cable[*]starting aid control cable[*]pressure gauges[*]temperature gauges[/ul][*]All regular lubricants for cables to be removed and left dry or replaced with arctic type lubricants.[*]Provide auxiliary engine compartment space heat sufficient to bring engine temperature to -32°C [-25°F].[*]-54°C [-65°F]electrical equipment and wiring.[*]Use -54°C [-65°F] hose.[*]Use -54°C [-65°F] ( rubber in the filter and dipstick expanders.[*] Use -54°C [-65°F] belts.[*]Extend fuel supply tank vent to a warm area such as to the engine compartment to prevent pulling frost into the tank.[*] Insulate all coolant, fuel and oil lines exposed to the elements. Insulate or cover with heat strip tape all coolant, fuel and oil lines exposed to the elements. [/ul] CAUTION[/align]
Anti-leak antifreezes are not recommended for use in Cummins® Engines. Although these antifreezes are chemically compatible with DCA water treatment, the anti-leak agents can clog the coolant filters, oil coolers and radiators making them ineffective.[/align]
Maintenance The accessory equipment used for low temperature operation and starting require maintenance on a regular schedule like other components on the engine. As an example, don't delay checking the performance of the manifold flame heater until the engine is to be started. Poorly or unscheduled maintenance always results in loss of productive time. Normal maintenance practices ought to be adhered to on all components. Maintenance suggestions for all engines are: [ul]Winterize 0°C to -23°C [32°F to -10°F][*]Keep fuel tanks full to reduce moisture condensation. Drain sediment daily. Keep fuel tanks full to reduce moisture condensation. Drain sediment daily.[*]Adhere to a lubricating oil change schedule necessary to maintain clean oil.[*]Daily check of preheater coil and electrical systems.[*]Weekly check of cold weather support systems. [/ul] [ul]Winterize -23°C to -32°C [-10°F to -25°F][*]Keep fuel tanks full to reduce moisture condensation. Drain sediment daily.[*]Adhere to oil change schedule necessary to maintain clean oil. Check level every two hours.[*]Daily check of preheater coil and electrical systems.[*]Weekly check of cold weather support systems.[*]Weekly check of temperature controls, thermostat and shutters. [/ul] [ul]Arctic Specifications -32°C to -54°C [-25°F to -65°F][*]Keep fuel tanks full to reduce moisture condensation. Drain sediment daily.[*]Adhere to oil change schedule necessary to maintain clean oil. Check level every two hours.[*]Daily check of preheater coil and electrical systems.[*]Weekly check of cold weather support systems.[*]Weekly check of temperature controls, thermostat, winter front, space heaters starters and starter electrical system. [/ul]

 

funny that you post this 2 days ago it was -45 f up here in alaska my truck was idling almost all day

 

Good reading. Expecting a cold front in NC?

 

I live at 4500ft and it's already been down to 12 degrees. I just happen to be looking for something else an ran across the bulletin. Like you said, it's some good reading and I thought others could use the actually info from Cummins instead of all the guessing that goes on about cold weather, fuel, additives and idling.

 

copied, pasted, and saved. [sm=smiley20.gif]

 

funny you post this once im in maine and the truck is acting up...dought its due to cold weahter..but still find it funny...i was fixing the fuel leak in 3 degrees today laying about in 4 inchs of snow with 5 ft snow banks in a plowed driveway...haha..

 

thanks.

 

Good information. Except for the info about idling I would not shut a diesel off for anything long period under +10F ifIwas depending on it to start again and wanted everything to be fine. From my experience in a big truck I never have a problem with waxing or gelling as long as I fuel up in a northern state where they sell better winter blend fuels that are typically good down to -10F. Sometimes though the wax crysals still form in there and restrict fuel flow through the filter if I've been idling all night (idling for long periods cools things down a lot and doesn't keep the fuel in the tank as warm) while sleeping down to 0F. Which results in loss of power until I get up to speed and run down the road for about 30 or 40 miles to melt the wax crsytalsgetting everything good and warm again. Last year I was out in Wyoming when they had a cold snap where it dropped down to -35F and I had to dump some Howes antigel in the tanks. From the looks of other trucks parked due to gelled fuel itdefinitely preventedthat and saved my rear but while I was taking rest breaks the filter still plugged up on me and gave me some power/acceleration issues that tended to stay with me longer than the usual 30 or 40 mile run to warm everything up.I could be wrong maybe -35F is normal for WY, WI, MI, etc ??? but I think for most of us guys in the lower 48 US winter blend fuel is more than sufficient for the temps we will normally see these are just my seat of the pants observations as an OTR driver.

 

holy s*it that is cold!!!!! jeeese triton do you live on top of a mountain or something?!?!? that would be siiick. a lotta good info in that read.

 

I agree... that's damn cold ! The worst I've seen it here is -5 degrees. Yes, I'm on top of a mountain so it's always colder here. I don't think it even got over 80 degrees this summer. There's many days during summer I have to leave the house in the morning with two shirts and a sweat shirt on !