Cold Weather Operation
Special precautions must be taken to protect the engine during cold weather. To
avoid engine damage, do not use any type of aerosol spray, e.g., ether, starting fluid
or brake cleaner to aid in starting the engine.
Winter Fronts
Winter fronts on Detroit™ Gen 5 Heavy Duty engines are seldom necessary due to
the modern design of the engine cooling system. The coolant thermostat is mounted
on the inlet side of the cooling system and regulates coolant flow from the radiator
into the engine. The thermostat regulates coolant flow to control the temperature of
the coolant within the coolant circuit. The following benefits are a result from
regulating the coolant at the inlet temperature side of the engine:
• Reduced thermal cycling of the engine
• Operating temperature is reached faster
• Improved vehicle heating because of better temperature regulation
The use of a winter front should be avoided as this has been shown to cause false
fault codes and performance issues with the engine and aftertreatment system.
Winter fronts can result in the following:
• Excessive fan run time due to higher Charge Air Cooler (CAC) outlet
temperatures resulting from low air flow through the CAC.
• Increased fuel consumption.
• Failure of the DEF system heaters to turn on when needed due to incorrect
temperature calculations. This results in fault codes, poor performance of the
aftertreatment system, and power reduction.
• Failure of critical emission equipment that will result in vehicle speed
inducement to a maximum of 5 mph.
There are two specific situations where a winter front may be temporarily needed:
• To improve cab heating while idling under extreme cold ambient temperature.
• When the ambient temperature remains below -30°C (-22°F) and the engine is
unable to maintain running coolant temperature of 80°C (175°F) during normal
over-the-road operation
If either of the above situations is encountered, a winter front may be temporarily
used. A minimum of 25% of the grille must be open in sectioned stripes that run
perpendicular to the charge air cooler tube flow direction. This assures even
cooling across each tube and reduces header-to-tube stress and possible failure.
Monitoring the Engine Operation
While the engine is operating, monitor the instrument panel indicators, battery
charge indicator and the oil pressure. Unnecessary idling should be avoided
whenever possible. When prolonged idling is necessary, maintain an engine speed
of 900 rpm.
Gen 5 DD Platform Operators Manual
All information subject to change without notice.
29
DDC-SVC-MAN-0217
Copyright © 2020 DETROIT DIESEL CORPORATION
