2007 Dodge Ram 3500 Pickup Owner Manual Diesel - Page 263

STARTING AND OPERATING 263 Engine Warm-Up Avoid full throttle operation when the engine is cold. When starting a cold engine, bring the engine up to operating speed slowly to allow the oil pressure to stabilize as the engine warms up. NOTE: High-speed, no-load running of a cold engine can result in excessive white smoke and poor engine performance. No-load engine speeds should be kept under 1,200 rpm during the warm-up period, especially in cold ambient temperature conditions. If temperatures are below 32°F (0°C), operate the engine at moderate speeds for 5 minutes before full loads are applied. Engine Idling - In Cold Weather Avoid prolonged idling in ambient temperatures below 0°F. Long periods of idling may be harmful to your engine because combustion chamber temperatures can drop so low that the fuel may not burn completely. Incomplete combustion allows carbon and varnish to form on piston rings and injector nozzles. Also, the unburned fuel can enter the crankcase, diluting the oil and causing rapid wear to the engine. NOTE: An optional driver-controlled high idle speed is available on automatic transmission equipped vehicles with speed control. This feature allows the driver to select an elevated idle speed between 1100 and 1500 rpms. Your dealer can enable this feature. NOTE: • If ambient temperatures are low and the coolant temperature is below 200°F (93°C), the engine idle 5